Tính hợp lí: a) $\left(-0,4\right) \dfrac{3}{8} \left(-0,6\right)$ b) $\dfrac{4}{5}-1,8 0,375 \dfrac{5}{8}$ c) $\dfrac{7}{3}.\left(-2,5\right).\dfrac{6}{7}$ d) \(\dfrac{7}{12}.\left(-2,34\ri...

5

VN

Võ Ngọc Phương

VIP

11 tháng 7 2023

Tính hợp lí:

a) $\left(-0,4\right)+\dfrac{3}{8}+\left(-0,6\right)$

$=\left[\left(-0,4\right)+\left(-0,6\right)\right]+\dfrac{3}{8}$

$=-1+\dfrac{3}{8}$

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

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

b) $\dfrac{4}{5}-1,8+0,375+\dfrac{5}{8}$

$=\dfrac{4}{5}-\dfrac{9}{5}+\dfrac{3}{8}+\dfrac{5}{8}$

$=-1+1$

$=0\\$

c) $\dfrac{7}{3}.\left(-2,5\right).\dfrac{6}{7}$

$=\dfrac{7}{3}.\dfrac{-5}{2}.\dfrac{6}{7}$

$=\dfrac{7}{3}.\dfrac{6}{7}.\dfrac{-5}{2}$

$=2.\dfrac{-5}{2}$

$=-5$

d) $\dfrac{7}{12}.\left(-2,34\right)-\dfrac{7}{12}.\left(-0,34\right)$

$=\dfrac{7}{12}.\left[\left(-2,34\right)+0,34\right]$

$=\dfrac{7}{12}.\left(-2\right)$

$=\dfrac{-7}{6}$

e) $\dfrac{-8}{3}.\dfrac{2}{11}-\dfrac{8}{3}:\dfrac{11}{9}$

$=\dfrac{8}{3}.\dfrac{-2}{11}-\dfrac{8}{3}.\dfrac{9}{11}$

$=\dfrac{8}{3}.\left(\dfrac{-2}{11}-\dfrac{9}{11}\right)$

$=\dfrac{8}{3}.-1$

$=\dfrac{-8}{3}$

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TN

Trần Nguyễn Phương Thảo

VIP

11 tháng 7 2023

Cảm ơn nha.

TN

Trần Nguyễn Phương Thảo

VIP

11 tháng 7 2023

1.Tính hợp lí

a) $0,7+\dfrac{-7}{19}-\left(-0,3\right)$

b) $\dfrac{5}{3}.\left(-2,5\right):\dfrac{5}{6}$

c) $0,6.\dfrac{-5}{17}-\dfrac{3}{5}.\dfrac{12}{17}$

d) $\dfrac{7}{4}.\dfrac{5}{2}-\dfrac{7}{4}.\dfrac{3}{2}$

Giúp tui với!

2

VN

Võ Ngọc Phương

VIP

11 tháng 7 2023

1. Tính hợp lí

a) $0,7+\dfrac{-7}{19}-\left(-0,3\right)$

$=\dfrac{7}{10}+\dfrac{-7}{19}+\dfrac{3}{10}$

$=\left(\dfrac{7}{10}+\dfrac{3}{10}\right)+\dfrac{-7}{19}$

$=1+\dfrac{-7}{19}$

$=\dfrac{12}{19}$

b) $\dfrac{5}{3}.\left(-2,5\right):\dfrac{5}{6}$

$=\dfrac{5}{3}.\dfrac{-5}{2}.\dfrac{6}{5}$

$=\left(\dfrac{5}{3}.\dfrac{6}{5}\right).\dfrac{-5}{2}$

$=2.\dfrac{-5}{2}$

$=-5$

c) $0,6.\dfrac{-5}{17}-\dfrac{3}{5}.\dfrac{12}{17}$

$=\dfrac{3}{5}.\dfrac{-5}{17}-\dfrac{3}{5}.\dfrac{12}{17}$

$=\dfrac{3}{5}.\left(\dfrac{-5}{17}-\dfrac{12}{17}\right)$

$=\dfrac{3}{5}.-1$

$=\dfrac{-3}{5}$

d) $\dfrac{7}{4}.\dfrac{5}{2}-\dfrac{7}{4}.\dfrac{3}{2}$

$=\dfrac{7}{4}.\left(\dfrac{5}{2}-\dfrac{3}{2}\right)$

$=\dfrac{7}{4}.1$

$=\dfrac{7}{4}$

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NQ

Nguyễn Quang Hưng

11 tháng 7 2023

a) $0, 7 + 19 - 7 - (- 0, 3)$

$= 10 7 + 19 - 7 + 10 3$

$= (10 7 + 10 3) + 19 - 7$

$= 1 + 19 - 7$

$= 19 12$

b) $3 5 . (- 2, 5) : 6 5$

$= 3 5 . 2 - 5 . 5 6$

$= (3 5 . 5 6) . 2 - 5$

$= 2. 2 - 5$

$= - 5$

c) $0, 6. 17 - 5 - 5 3 . 17 12$

$= 5 3 . 17 - 5 - 5 3 . 17 12$

$= 5 3 . (17 - 5 - 17 12)$

$= 5 3 . - 1$

$= 5 - 3$

d) $4 7 . 2 5 - 4 7 . 2 3$

$= 4 7 . (2 5 - 2 3)$

$= 4 7 .1$

$= 4 7$

mình giúp rùi đó nhớ tick mình nha

CH

Chử Hải Yến

29 tháng 5 2022

Tính hợp lý:

$A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}$ $B=\left(\dfrac{4}{5}+\dfrac{1}{2}\right):\left(\dfrac{3}{13}-\dfrac{8}{13}\right)$

$C=\left(\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}\right):\left(\dfrac{5}{12}+1-\dfrac{7}{11}\right)$

Tính bằng cách hợp lý:$a,\dfrac{2}{3}+\left(\dfrac{5}{7}+\dfrac{-2}{3}\right)$ $b,\left(\dfrac{-1}{4}+\dfrac{5}{8}\right)+\dfrac{-3}{8}$$c,\dfrac{7}{5}.\dfrac{8}{19}+\dfrac{7}{5}.\dfrac{12}{19}-\dfrac{7}{5}.\dfrac{1}{19}$$d,6\dfrac{3}{10}-\left(3\dfrac{4}{7}+2\dfrac{3}{10}\right)$$e,\left(31,12-5,97\right)-\left(-68,88+4,03\right)$$h,3,7.\left(-10,56\right)+3,7.110,56$ ...

1

NL

Nguyễn Lê Phước Thịnh

29 tháng 5 2022

a: $A=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}=\dfrac{42}{72}+\dfrac{5}{72}-\dfrac{22}{72}=\dfrac{25}{72}$

b: $B=\dfrac{8+5}{10}:\dfrac{-5}{13}=\dfrac{13}{10}\cdot\dfrac{13}{-5}=-\dfrac{169}{100}$

c: $C=\left(\dfrac{88}{132}-\dfrac{33}{132}+\dfrac{60}{132}\right):\left(\dfrac{55}{132}+\dfrac{132}{132}-\dfrac{84}{132}\right)$

$=\dfrac{88-33+60}{55+132-84}=\dfrac{115}{103}$

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KJ

❖ Khang/GD❄ 『ʈєɑɱ❖Hoàng๖ۣۜGia☆』

12 tháng 3 2022

Tính bằng cách hợp lí giá trị của biểu thức. A = $\left(3-\dfrac{1}{4} +\dfrac{3}{2}\right)$- $\left(5+\dfrac{1}{3}-\dfrac{5}{6}\right)$-$\left(6-\dfrac{7}{4}+\dfrac{3}{2}\right)$ B...

0

HP

Hồng Phong Đoàn

19 tháng 10 2023

#Toán lớp 7

2

NM

Nguyễn Minh Dương

VIP

19 tháng 10 2023

$A=\left(3-\dfrac{1}{4}+\dfrac{3}{2}\right)-\left(5+\dfrac{1}{3}-\dfrac{5}{6}\right)-\left(6-\dfrac{7}{4}+\dfrac{2}{3}\right)\\ \Rightarrow A=3-\dfrac{1}{4}+\dfrac{3}{2}-5-\dfrac{1}{3}+\dfrac{5}{6}-6+\dfrac{7}{4}-\dfrac{2}{3}\\ \Rightarrow A=\left(3-5-6\right)-\left(\dfrac{1}{4}+\dfrac{7}{4}\right)+\left(\dfrac{3}{2}+\dfrac{5}{6}-\dfrac{2}{3}\right)\\ \Rightarrow A=-8-\dfrac{3}{2}+\dfrac{5}{3}\\ =-\dfrac{47}{6}.\\ B=0,5+\dfrac{1}{3}+0,4+\dfrac{5}{7}+\dfrac{1}{6}-\dfrac{4}{35}+\dfrac{1}{41}$

$\Rightarrow B=\left(0,5+0,4\right)+\left(\dfrac{1}{3}+\dfrac{1}{6}\right)+\left(\dfrac{5}{7}-\dfrac{4}{35}\right)+\dfrac{1}{41}\\ \Rightarrow B=\dfrac{9}{10}+\dfrac{1}{2}+\dfrac{3}{5}+\dfrac{1}{41}\\ \Rightarrow B=2+\dfrac{1}{41}\\ \Rightarrow B=\dfrac{83}{41}.$

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NP

Ngô Phúc Nhã Uyên

VIP

29 tháng 10 2023

-_-

QN

Quỳnh nga

11 tháng 4 2022

Thực hiện các phép tính:

a,$\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)$

b, $10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+3:15\%$

c. $4\dfrac{3}{4}+\left(-0,37\right)+\dfrac{1}{8}+\left(-1,8\right)+\left(-2,5\right)+3\dfrac{1}{12}$

1

DC

dâu cute

11 tháng 4 2022

a, = (58/9 + 7/11) - (40/9 - 26/11)

= 701/99 - 206/99

= 5

b, = 51/5 - 11/2 . 60/11 + 3 : 3/20

= 51/5 - 30 + 20

= -99/5 + 20

= 1/5

c, = 19/4 + (-0,37) + 1/8 + (-1,8) + (-2,5) + 37/12

= 219/50 + -67/40 + 7/12

= 1973/600

tính giá trị biểu thức...

T

títtt

7 tháng 1

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...

#Toán lớp 11

1

NL

Nguyễn Lê Phước Thịnh

7 tháng 1

a: $A=\dfrac{9^4}{3^2}=\dfrac{\left(3^2\right)^4}{3^2}=\dfrac{3^8}{3^2}=3^6$=729

b: $B=81\left(\dfrac{5}{3}\right)^4=81\cdot\dfrac{5^4}{3^4}=\dfrac{81}{3^4}\cdot5^4=5^4=625$

c: $C=\left(\dfrac{4}{7}\right)^{-4}\cdot\left(\dfrac{2}{7}\right)^3$

$=\left(\dfrac{7}{4}\right)^4\cdot\left(\dfrac{2}{7}\right)^3$

$=\dfrac{7^4}{4^4}\cdot\dfrac{2^3}{7^3}$

$=\dfrac{2^3}{4^4}\cdot7$

$=\dfrac{2^3}{2^8}\cdot7=\dfrac{7}{2^5}=\dfrac{7}{32}$

d: $D=7^{-6}\cdot\left(\dfrac{2}{3}\right)^0\left(\dfrac{7}{5}\right)^6$

$=7^{-6}\left(\dfrac{7}{5}\right)^6$

$=\dfrac{1}{7^6}\cdot\dfrac{7^6}{5^6}=\dfrac{1}{5^6}=\dfrac{1}{15625}$

e: $E=8^3:\left(\dfrac{2}{3}\right)^5\cdot\left(\dfrac{1}{3}\right)^2$

$=2^6:\dfrac{2^5}{3^5}\cdot\dfrac{1}{3^2}$

$=2^6\cdot\dfrac{3^5}{2^5}\cdot\dfrac{1}{3^2}$

$=\dfrac{2^6}{2^5}\cdot\dfrac{3^5}{3^2}=3^3\cdot2=54$

f: $F=\left(\dfrac{7}{9}\right)^{-2}\cdot\left(\dfrac{1}{\sqrt{3}}\right)^8$

$=\left(\dfrac{9}{7}\right)^2\cdot\left(\dfrac{1}{3}\right)^4$

$=\dfrac{9^2}{7^2}\cdot\dfrac{1}{3^4}=\dfrac{9^2}{3^4}\cdot\dfrac{1}{7^2}=\dfrac{81}{81}\cdot\dfrac{1}{49}=\dfrac{1}{49}$

g: $G=\left(-\dfrac{4}{5}\right)^{-2}\cdot\left(\dfrac{2}{5}\right)^2\cdot\left(\sqrt{2}\right)^3$

$=\left(-\dfrac{5}{4}\right)^2\cdot\left(\dfrac{2}{5}\right)^2\cdot2\sqrt{2}$

$=\dfrac{25}{16}\cdot\dfrac{4}{25}\cdot2\sqrt{2}=\dfrac{4}{16}\cdot2\sqrt{2}=\dfrac{8\sqrt{2}}{16}=\dfrac{\sqrt{2}}{2}$

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NT

Nguyễn Thị Mỹ Loan♍13/9

21 tháng 6 2023

$a,\dfrac{-6}{11}:\left(\dfrac{3}{5}:\dfrac{4}{11}\right)$ b,$\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}$$c,\left(\dfrac{4}{5}+\dfrac{1}{2}\right):\left(\dfrac{3}{13}-\dfrac{8}{13}\right)$ $d,\left(\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}\right):\left(\dfrac{5}{12}-1-\dfrac{7}{11}\right)$ Giúp mik...

#Toán lớp 7

1

TT

Thư Thư

21 tháng 6 2023

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

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

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

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

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

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

$=\dfrac{9}{5}$

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

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

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

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

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

$=\dfrac{79}{24}$

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

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

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

$=\dfrac{62}{49}$

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

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QN

quan nguyen hoang

19 tháng 2 2022