Bài 1: Tính: A=$\left(-2\right).\left(-3\right)-5.\left|-5\right| 125.\left(\dfrac{-1}{5}\right)^2$ B=\(\left(-3\right).\left|-7\right|-\left(-4\right).\left|5\right| \dfrac{1}{3}.\left|-9\right|\...

#Toán lớp 6

5

KL

Khánh Linh

1 tháng 8 2017

1. A = (-2)(-3) - 5.|-5| + 125.$\left(-\dfrac{1}{5}\right)^2$
= 6 - 25 + 125.$\dfrac{1}{25}$
= -19 + 5
= -14
@Shine Anna

QD

Quang Duy

1 tháng 8 2017

Đăng ít thôi

Tính giá trị của các biểu thức sau : a)$\left(7+3\dfrac{1}{4}-\dfrac{3}{5}\right)$+(0,4 - 5) - $\left(4\dfrac{1}{4}-1\right)$ b)$\dfrac{2}{3}$ - $\left[\left(-\dfrac{7}{4}\right)-\left(\dfrac{1}{2}+\dfrac{3}{8}\right)\right]$ c)$\left(9-\dfrac{1}{2}-\dfrac{3}{4}\right)$:$\left(7-\dfrac{1}{4}-\dfrac{5}{8}\right)$ d)3 - $\dfrac{1-\dfrac{1}{7}}{1+\dfrac{1}{7}}$ giúp mình nhé trả lời mình cho tick cảm ơn các bạn...

NT

Nguyễn Thị Mỹ Loan♍13/9

21 tháng 6 2023

1

Y

YangSu

21 tháng 6 2023

$a,\left(7+3\dfrac{1}{4}-\dfrac{3}{5}\right)+\left(0,4-5\right)-\left(4\dfrac{1}{4}-1\right)$

$=\left(7+\dfrac{13}{4}-\dfrac{3}{5}\right)-\dfrac{23}{5}-\left(\dfrac{17}{4}-1\right)$

$=7+\dfrac{13}{4}-\dfrac{3}{5}-\dfrac{23}{5}-\dfrac{17}{4}+1$

$=\left(7+1\right)+\left(\dfrac{13}{4}-\dfrac{17}{4}\right)-\left(\dfrac{3}{5}+\dfrac{23}{5}\right)$

$=8-\dfrac{4}{4}-\dfrac{26}{5}$

$=7-\dfrac{26}{5}$

$=\dfrac{9}{5}$

$b,\dfrac{2}{3}-\left[\left(-\dfrac{7}{4}\right)-\left(\dfrac{1}{2}+\dfrac{3}{8}\right)\right]$

$=\dfrac{2}{3}-\left(-\dfrac{7}{4}-\dfrac{1}{2}-\dfrac{3}{8}\right)$

$=\dfrac{2}{3}-\left(-\dfrac{14}{8}-\dfrac{4}{8}-\dfrac{3}{8}\right)$

$=\dfrac{2}{3}-\left(-\dfrac{21}{8}\right)$

$=\dfrac{2}{3}+\dfrac{21}{8}$

$=\dfrac{79}{24}$

$c,\left(9-\dfrac{1}{2}-\dfrac{3}{4}\right):\left(7-\dfrac{1}{4}-\dfrac{5}{8}\right)$

$=\left(\dfrac{36}{4}-\dfrac{2}{4}-\dfrac{3}{4}\right):\left(\dfrac{56}{8}-\dfrac{2}{8}-\dfrac{5}{8}\right)$

$=\dfrac{31}{4}:\dfrac{49}{8}$

$=\dfrac{62}{49}$

$d,3-\dfrac{1-\dfrac{1}{7}}{1+\dfrac{1}{7}}=3-\dfrac{\dfrac{7}{7}-\dfrac{1}{7}}{\dfrac{7}{7}+\dfrac{1}{7}}=3-\left(\dfrac{6}{7}:\dfrac{8}{7}\right)=3-\dfrac{3}{4}=\dfrac{9}{4}$

Đúng(5)

LA

Lê Anh Tuấn

6 tháng 10 2021

Bài 8:
b)$\left(\dfrac{-4}{3}\right)+\left(\dfrac{-2}{5}\right)+\left(\dfrac{-3}{2}\right)$
c) $\dfrac{4}{5}-\left(\dfrac{-2}{7}\right)-\dfrac{-7}{10}$
d) $\dfrac{2}{3}-\left[\left(\dfrac{-7}{4}\right)-\left(\dfrac{1}{2}+\dfrac{3}{8}\right)\right]$

2

NH

Nguyễn Hoàng Minh

6 tháng 10 2021

$b,=-\dfrac{40}{30}-\dfrac{12}{30}-\dfrac{45}{30}=-\dfrac{97}{30}\\ c,=\left(\dfrac{4}{5}+\dfrac{7}{10}\right)+\dfrac{2}{7}=\dfrac{3}{2}+\dfrac{2}{7}=\dfrac{25}{14}\\ d,=\dfrac{2}{3}+\dfrac{7}{4}+\dfrac{1}{2}+\dfrac{3}{8}\\ =\left(\dfrac{2}{3}+\dfrac{1}{2}\right)+\left(\dfrac{7}{4}+\dfrac{3}{8}\right)=\dfrac{7}{6}+\dfrac{17}{8}=\dfrac{79}{24}$

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NL

Nguyễn Lê Phước Thịnh

6 tháng 10 2021

c: $\dfrac{4}{5}-\dfrac{-2}{7}-\dfrac{-7}{10}$

$=\dfrac{56}{70}+\dfrac{20}{70}+\dfrac{49}{70}$

$=\dfrac{125}{70}=\dfrac{25}{14}$

Bài 1: a,$3^7$ : $3^5$- $\left(\dfrac{5}{17}\right)^0$ b,$\left(\dfrac{5}{2}\right)^{13}$ : $\left(\dfrac{1}{2}+2\right)^3$ c, 8.$\left(\dfrac{1}{4}\right)^3$ +$\left(\dfrac{2}{27}\right)^0$ - $\dfrac{1}{8}$ Bài 2 : a, $\dfrac{3^4.4^4}{6^4}$ b,$\dfrac{15^3}{10^3}$ c, $\dfrac{4^2.12^5}{9^2.2^{10}}$ d, $\dfrac{6^2+5.2^2+4}{15}$ Bài 3...

NG

Nguyễn Gia BảoB

7 tháng 9 2023

4

VN

Võ Ngọc Phương

VIP

7 tháng 9 2023

Bài 1:

a) $3^7:3^5-\left(\dfrac{5}{17}\right)^0=3^{7-5}-1=3^2-1=9-1=8$

b) $\left(\dfrac{5}{2}\right)^{13}:\left(\dfrac{1}{2}+2\right)^3$

$=\left(\dfrac{5}{2}\right)^{13}:\left(\dfrac{5}{2}\right)^3$

$=\left(\dfrac{5}{2}\right)^{10}$

c) $8.\left(\dfrac{1}{4}\right)^3+\left(\dfrac{2}{27}\right)^0-\dfrac{1}{8}$

$=8.\dfrac{1}{64}+1-\dfrac{1}{8}$

$=\dfrac{1}{8}+1-\dfrac{1}{8}$

$=1$

Bài 2:

a) $\dfrac{3^4.4^4}{6^4}=\dfrac{3^4.\left(2^2\right)^4}{\left(2.3\right)^4}=\dfrac{3^4.2^8}{2^4.3^4}=\dfrac{2^8}{2^4}=2^4=16$

b) $\dfrac{15^3}{10^3}=\dfrac{\left(3.5\right)^3}{ \left(2.5\right)^3}=\dfrac{3^3.5^3}{2^3.5^3}=3^3:2^3=\dfrac{27}{8}$

c) $\dfrac{4^2.12^5}{9^2.2^{10}}=\dfrac{\left(2^2\right)^2.\left[3.\left(2^2\right)\right]^5}{\left(3^2\right)^2.2^{10}}=\dfrac{2^4.3^5.2^{10}}{3^4.2^{10}}=2^4.3=16.3=48$

d) $\dfrac{6^2+5.2^2+4}{15}=\dfrac{\left(2.3\right)^2+5.2^2+2^2}{15}=\dfrac{2^2.3^2+5.2^2+2^2}{15}=\dfrac{2^2\left(3^2+5+1\right)}{15}=\dfrac{2^2.15}{15}=2^2=4$

Bài 3:

a) $\dfrac{\left(\dfrac{2}{3}\right)^3.\left(\dfrac{-3}{4}\right)^2.\left(-1\right)^5}{\left(\dfrac{2}{5}\right)^2.\left(\dfrac{-5}{12}\right)^2}$

$=\dfrac{\left(\dfrac{2}{3}\right)^3.\left(\dfrac{-3}{4}\right)^2.-1}{\left[\dfrac{2}{5}.\left(\dfrac{-5}{12}\right)\right]^2}$

$=\dfrac{\left(\dfrac{2}{3}\right)^3. \left(\dfrac{-3}{4}\right)^2.-1}{\left(\dfrac{-1}{6}\right)^2}$

$=\left(\dfrac{2}{3}\right)^3.\left[\left(\dfrac{-3}{4}\right).-6\right]^2.-1$

$=\left(\dfrac{2}{3}\right)^3.\left(\dfrac{9}{2}\right)^2.-1$

$=\left(\dfrac{2}{3}\right)^2.\dfrac{2}{3}.\left(\dfrac{9}{2}\right)^2.-1$

$=\left(\dfrac{2}{3}.\dfrac{9}{2}\right)^2.\dfrac{2}{3}.-1$

$=9.\dfrac{2}{3}.-1$

$=6.-1=-6$

b) $\dfrac{6^6+6^3.3^3+3^6}{-73}=\dfrac{\left(2.3\right)^6+\left(2.3\right)^3.3^3+3^6}{-73}=\dfrac{2^6.3^6+2^3.3^3.3^3+3^6}{-73}=\dfrac{2^6.3^6+2^3.3^6+3^6}{-73}=\dfrac{3^6\left(2^6+2^3+1\right)}{-73}=\dfrac{3^6.73}{-73}=\dfrac{3^6}{-1}=\left(-3\right)^6$

$#Wendy.Dang$

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VN

Võ Ngọc Phương

VIP

7 tháng 9 2023

Lần sau bnn gửi từng bài thôi nha, chứ như vầy nhiều quá thì làm không nổi mất. đánh máy nãy giờ lú luôn gòi nè :))

NA

Người Âm

14 tháng 8 2021

$a,\left(\dfrac{4}{9}+\dfrac{1}{3}\right)^2$

$b,\left(\dfrac{1}{2}-\dfrac{3}{5}\right)^3$

c,$\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{4}\right)^4$

$\left(\dfrac{3}{4}\right)^3:\left(\dfrac{3}{4}\right)^2:\left(\dfrac{-3}{2}\right)^3$

#Toán lớp 6

1

NL

Nguyễn Lê Phước Thịnh

14 tháng 8 2021

a: $\left(\dfrac{4}{9}+\dfrac{1}{3}\right)^2=\dfrac{49}{81}$

b: $\left(\dfrac{1}{2}-\dfrac{3}{5}\right)^3=-\dfrac{1}{1000}$

c: $\left(-\dfrac{10}{3}\right)^5\cdot\left(-\dfrac{6}{4}\right)^4=-\dfrac{6250}{3}$

d: $\left(\dfrac{3}{4}\right)^3:\left(\dfrac{3}{4}\right)^2:\left(-\dfrac{3}{2}\right)^3=-\dfrac{2}{9}$

NL

Nguyen Le Tuong Vy

12 tháng 7 2023

Tính:

a/$A=\left(-0,75-\dfrac{1}{4}\right):\left(-5\right)+\dfrac{1}{48}-\left(\dfrac{-1}{6}\right):\left(-3\right)$

b/$B=\left(\dfrac{6}{25}-1,24\right):\dfrac{3}{7}:\left[\left(3\dfrac{1}{2}-3\dfrac{2}{3}\right):\dfrac{1}{14}\right]$

3

H9

HT.Phong (9A5)

12 tháng 7 2023

a) $A=\left(-0,75-\dfrac{1}{4}\right):\left(-5\right)+\dfrac{1}{48}-\left(-\dfrac{1}{6}\right):\left(-3\right)$

$A=\left(-0,75-0,25\right):\left(-5\right)+\dfrac{1}{48}-\left(-\dfrac{1}{6}\right)\cdot\dfrac{-1}{3}$

$A=\left(-1\right):\left(-5\right)+\dfrac{1}{48}-\dfrac{1}{18}$

$A=\dfrac{1}{5}+\dfrac{1}{48}-\dfrac{1}{18}$

$A=\dfrac{119}{720}$

b) $B=\left(\dfrac{6}{25}-1,24\right):\dfrac{3}{7}:\left[\left(3\dfrac{1}{2}-3\dfrac{2}{3}\right):\dfrac{1}{14}\right]$

$B=\left(0,24-1,24\right):\dfrac{3}{7}:\left[\left(\dfrac{7}{2}-\dfrac{11}{3}\right):\dfrac{1}{14}\right]$

$B=-1:\dfrac{3}{7}:\left(-\dfrac{1}{6}:\dfrac{1}{14}\right)$

$B=-\dfrac{7}{3}:-\dfrac{7}{3}$

$B=1$

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NT

Nguyễn Thị Thương Hoài

Giáo viên VIP

12 tháng 7 2023

a, A = (-0,75 - $\dfrac{1}{4}$) : (-5) + $\dfrac{1}{48}$ - (- $\dfrac{1}{6}$) : (-3)

A = -(0,75 + 0,25): (-5) + $\dfrac{1}{48}$ - $\dfrac{1}{18}$

A = -1 : (-5) + $\dfrac{1}{48}$ - $\dfrac{1}{18}$

A = $\dfrac{1}{5}$ + $\dfrac{1}{48}$ - $\dfrac{1}{18}$

A = $\dfrac{53}{240}$ - $\dfrac{1}{18}$

A = $\dfrac{119}{720}$

b, B = ($\dfrac{6}{25}$ - 1,24): $\dfrac{3}{7}$: [(3$\dfrac{1}{2}$ - 3$\dfrac{2}{3}$): $\dfrac{1}{14}$]

B = (0,24 - 1,24): $\dfrac{3}{7}$:[($\dfrac{7}{2}$-$\dfrac{11}{3}$): $\dfrac{1}{14}$]

B = -1: $\dfrac{3}{7}$:[ (-$\dfrac{1}{6}$ : $\dfrac{1}{14}$)]

B = -1: $\dfrac{3}{7}$: (- $\dfrac{7}{3}$)

B = 1 $\times$ $\dfrac{7}{3}$ $\times$ $\dfrac{3}{7}$

B = 1

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NK

Nezuko Kamado

29 tháng 10 2021

Tìm x :

1) $\left(-0,75x+\dfrac{5}{2}\right).\dfrac{4}{7}-\left(-\dfrac{1}{3}\right)=-\dfrac{5}{6}$

2) $\left(4x-9\right)\left(2,5+\dfrac{-7}{3}x\right)=0$

3) $\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0$

4)$\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\dfrac{-64}{125}$

1

NL

Nguyễn Lê Phước Thịnh

29 tháng 10 2021

3: $\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0$

$\Leftrightarrow\left|x-\dfrac{3}{4}\right|=\dfrac{1}{2}$

$\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{3}{4}=\dfrac{1}{2}\\x-\dfrac{3}{4}=-\dfrac{1}{2}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{4}\\x=\dfrac{1}{4}\end{matrix}\right.$

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LH

Lan Hương

27 tháng 9 2023

bài 2: 1, $\left(\dfrac{5}{6}\right)^{10}.\left(\dfrac{3}{10}\right)^{10}$2,$\left(\dfrac{4}{7}\right)^{19}:\left(\dfrac{-12}{35}\right)^{19}$ 3,$\left(\dfrac{-3}{7}\right)^7:\left(\dfrac{-3}{5}\right)$

3

AH

Akai Haruma

Giáo viên

27 tháng 9 2023

Lời giải:

1.

$(\frac{5}{6})^{10}.(\frac{3}{10})^{10}=(\frac{5}{6}.\frac{3}{10})^{10}=(\frac{1}{4})^{10}$

$=\frac{1}{4^{10}}$

2.

$(\frac{4}{7})^{19}: (\frac{-12}{35})^{19}=(\frac{4}{7}: \frac{-12}{35})^{19}=(\frac{-5}{3})^{19}$

3.

$(\frac{-3}{7})^7:\frac{-3}{5}=\frac{(-3)^7}{7^7}.\frac{5}{-3}=\frac{5.(-3)^6}{7^7}=\frac{5.3^6}{7^7}$

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LH

Lan Hương

27 tháng 9 2023

giúp mình với ạ

NP

Nguyễn Phương Chi

12 tháng 9 2021

Tính

a) $\dfrac{13}{50}.\left(-15.5\right):\dfrac{13}{50}.84\dfrac{1}{2}$

b) $\dfrac{\left(-0,7\right)^2.\left(-5\right)^3}{\left(-2\dfrac{1}{3}\right)^3.\left(1\dfrac{1}{2}\right)^4.\left(-1\right)^5}$

2

NH

Nguyễn Hoàng Minh

12 tháng 9 2021

$a,=\dfrac{13}{50}\cdot\dfrac{50}{13}\cdot\left(-\dfrac{31}{2}\right)\cdot\dfrac{169}{2}=-\dfrac{5239}{2}\\ b,=\dfrac{-\dfrac{49}{100}\cdot\left(-125\right)}{-\dfrac{343}{27}\cdot\dfrac{81}{16}\cdot\left(-1\right)}=\dfrac{\dfrac{245}{4}}{\dfrac{1029}{16}}=\dfrac{245}{4}\cdot\dfrac{16}{1029}=\dfrac{20}{21}$

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I

ILoveMath

12 tháng 9 2021

a) $\dfrac{13}{50}.\left(-15.5\right):\dfrac{13}{50}.84\dfrac{1}{2}=\dfrac{13}{50}.-75:\dfrac{13}{50}.\dfrac{169}{2}=-\dfrac{75.169}{2}=-\dfrac{12675}{2}$

b) $\dfrac{\left(-0,7\right)^2.\left(-5\right)^3}{\left(-2\dfrac{1}{3}\right)^3.\left(1\dfrac{1}{2}\right)^4.\left(-1\right)^5}=\dfrac{0,49.\left(-125\right)}{-\dfrac{343}{27}.\dfrac{81}{16}.\left(-1\right)}=-\dfrac{\dfrac{245}{4}}{\dfrac{1029}{16}}=\dfrac{20}{21}$

a, $5^6$ : $5^5$ + $\left(\dfrac{4}{9}\right)^0$ b,$\left(\dfrac{3}{7}\right)^{21}$ : $\left(1-\dfrac{40}{49}\right)^3$ c, 3.$\left(\dfrac{2}{3}\right)^3$ -$\left(\dfrac{-52}{3}\right)^0$ +$\dfrac{4}{9}$ Mọi người giúp mình...

NG

Nguyễn Gia BảoB

7 tháng 9 2023