a. $\dfrac{2}{15} 3$ b. $2-\dfrac{7}{4}$ c. $\dfrac{17}{6}-\dfrac{11}{12}\times6$ d.$\dfrac{14}{17}:7-\dfrac{15}{34}$bài 3: a. x : 23 =146 b. x \...

#Toán lớp 4

4

O

★彡✿ทợท彡★

9 tháng 5 2022

B1 :

a) $\dfrac{2}{15}+3=\dfrac{2}{15}+\dfrac{15}{5}=\dfrac{17}{5}$

b) $2-\dfrac{7}{4}=\dfrac{8}{4}-\dfrac{7}{4}=\dfrac{1}{4}$

c) $\dfrac{17}{6}-\dfrac{11}{12}\times6=\dfrac{17}{6}-\dfrac{11}{2}=-\dfrac{8}{3}$

d) $\dfrac{14}{17}:7-\dfrac{15}{34}=\dfrac{2}{17}-\dfrac{5}{34}=\dfrac{4}{34}-\dfrac{5}{34}=-\dfrac{1}{34}$

B3 :

$x:23=146$

$x=146\times23$

$x=3358$

b) $x\times38=4066$

$x=4066:38$

$x=107$

c) $787+x\times67=2658$

$x\times67=2658-787$

$x\times67=1871$

$x=1871:67$

$x=\dfrac{1871}{67}$

YA

You are my sunshine

9 tháng 5 2022

từng bài thôi

Tính: a) $\dfrac{13}{14}$-$\dfrac{-7}{8}$+$\dfrac{-3}{2}$b) $\dfrac{5}{17}$+$\dfrac{-15}{34}$.$\dfrac{2}{5}$c) $\dfrac{1}{5}$:$\dfrac{1}{10}$-$\dfrac{1}{3}$.($\dfrac{6}{5}$-$\dfrac{2}{4}$)d) $\dfrac{-3}{4}$:($\dfrac{12}{-5}$-$\dfrac{-7}{10}$)*Lưu ý: Không viết luôn kết quả, giải chi...

AT

Anh Tuấn Đào

7 tháng 4 2022

#Toán lớp 6

1

K

Knight™

7 tháng 4 2022

$a,\dfrac{13}{14}\cdot\dfrac{-7}{8}+\dfrac{-3}{2}$

$=-\dfrac{13}{16}+\dfrac{-3}{2}$

$=-\dfrac{13}{16}+\dfrac{-24}{16}$

$=-\dfrac{37}{16}$

$b,\dfrac{5}{17}+\dfrac{-15}{34}\cdot\dfrac{2}{5}$

$=\dfrac{5}{17}+\dfrac{-3}{17}$

$=\dfrac{2}{17}$

$c,\dfrac{1}{5}:\dfrac{1}{10}-\dfrac{1}{3}\cdot\left(\dfrac{6}{5}-\dfrac{2}{4}\right)$

$=2-\dfrac{1}{3}\cdot\dfrac{7}{10}$

$=2-\dfrac{7}{30}$

$=\dfrac{53}{30}$

$d,\dfrac{-3}{4}:\left(\dfrac{12}{-5}-\dfrac{-7}{10}\right)$

$=\dfrac{-3}{4}:\dfrac{-17}{10}$

$=\dfrac{15}{34}$

Đúng(3)

AT

Anh Tuấn Đào

7 tháng 4 2022

Ý a anh chép sai đề bài nên làm sai rùi kìa!~

a) $\dfrac{5}{7}$+$\dfrac{3}{4}$.$\dfrac{-11}{2}$b) ($\dfrac{12}{17}$+$\dfrac{19}{7}$) - ($\dfrac{-5}{17}$-$\dfrac{3}{7}$)c)...

PV

Phạm Vũ Hà My

15 tháng 11 2021

#Toán lớp 7

1

NH

Nguyễn Hoàng Minh

15 tháng 11 2021

$a,=\dfrac{5}{7}-\dfrac{33}{8}=-\dfrac{191}{56}\\ b,=\left(\dfrac{12}{17}+\dfrac{5}{17}\right)+\left(\dfrac{19}{7}+\dfrac{3}{7}\right)=1+3=4\\ c,=\left(0,125\cdot8\right)^{12}-\left(\dfrac{45}{15}\right)^3=1-3^3=-26\\ d,=\left(-\dfrac{1}{3}\right)\left(5\dfrac{2}{7}-2\dfrac{2}{7}\right)=-\dfrac{1}{3}\cdot3=-1\\ e,=\dfrac{3^4\cdot3^6}{3^9}=3$

PV

Phạm Vũ Hà My

15 tháng 11 2021

Thank you ^^

Tính:a) $\dfrac{-5}{9}$$+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}$ b)$\left(\dfrac{-5}{12}+\dfrac{6}{11}\right)+\left(\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}\right)$c) A= $49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)$d)...

QA

Quỳnh Anh Daisy

25 tháng 7 2021

#Toán lớp 6

3

OY

OH-YEAH^^

25 tháng 7 2021

a) $\dfrac{-5}{9}+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}$

=$\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)+\dfrac{-2}{11}$

=$\left(-1\right)+1+\dfrac{-2}{11}$

=$\dfrac{-2}{11}$

b) $\left(\dfrac{-5}{12}+\dfrac{6}{11}\right)+\left(\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}\right)$

=$\dfrac{-5}{12}+\dfrac{6}{11}+\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}$

=$\left(\dfrac{-5}{12}+\dfrac{5}{12}\right)+\left(\dfrac{6}{11}+\dfrac{5}{11}\right)+\dfrac{7}{17}$

=$0+0+\dfrac{7}{17}$

=$\dfrac{7}{17}$

c) A= $49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)$

A=$49\dfrac{8}{23}-5\dfrac{7}{32}-14\dfrac{8}{23}$

A=$\left(49\dfrac{8}{23}-14\dfrac{8}{23}\right)-5\dfrac{7}{32}$

A=$35-5\dfrac{7}{32}$

A=$35-\dfrac{167}{32}=\dfrac{953}{32}$

d) C=$\dfrac{-3}{7}.\dfrac{5}{9}+\dfrac{4}{9}.\dfrac{-3}{7}+2\dfrac{3}{7}$

C=$\dfrac{-3}{7}.\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{17}{7}$

C=$\dfrac{-3}{7}.1+\dfrac{17}{7}$

C=$\dfrac{-3}{7}+\dfrac{17}{7}=2$

HD

Hải Đức

25 tháng 7 2021

a, `(-5)/9+8/15+(-2)/11+4/(-9)+7/15`

`=-5/9+8/15-2/11-4/9+7/15`

`=(-5/9-4/9)+(8/15+7/15)-2/11`

`=-9/9+15/15-2/11`

`=-1+1-2/11`

`=-2/11`

b, `((-5)/12+6/11)+(7/17+5/11+5/12)`

`=-5/12+6/11+7/17+5/11+5/12`

`=(-5/12+5/12)+(6/11+5/11)+7/17`

`=0+11/11+7/17`

`=1+7/17`

`=17/17+7/17`

`=24/17`

c, `A=49 8/23 - (5 7/32 + 14 8/23)`

`A=49 8/23 - 5 7/32 - 14 8/23`

`A=(49 8/23 - 14 8/23)-5 7/32`

`A=35 - 167/32`

`A=953/32`

d, `C=(-3)/7.5/9+4/9.(-3)/7+2 3/7`

`C=-3/7 . 5/9-4/9 . 3/7+17/7`

`C=-3/7.(5/9+4/9)+17/7`

`C=-3/7 . 1+17/7`

`C=2`

>, <, = ?$\dfrac{4}{11}$ ... $\dfrac{6}{11}$ $\dfrac{6}{7}$ ... $\dfrac{12}{14}$$\dfrac{15}{17}$ ... $\dfrac{10}{17}$ ...

GB

Giang Bùi

6 tháng 1 2021

#Toán lớp 5

5

LT

Lê Trang

6 tháng 1 2021

$\dfrac{4}{11}< \dfrac{6}{11}$

$\dfrac{6}{7}=\dfrac{12}{14}$

$\dfrac{15}{17}>\dfrac{10}{17}$

$\dfrac{2}{3}< \dfrac{3}{4}$

VN

Vi Ngô Thị Tú

8 tháng 12 2022

$\frac{4}{11} < \frac{6}{11}$

$\frac{6}{7} = \frac{12}{14}$

$\frac{15}{17} > \frac{10}{17}$

$\frac{2}{3} < \frac{3}{4}$

Bài 4: tìm x:a) $\dfrac{4}{3}$ + (1,25 - x) = 2,25b) $\dfrac{17}{6}$ - (x - $\dfrac{7}{6}$ ) = $\dfrac{7}{4}$c) 4 - (2x + 1) = 3 - $\dfrac{1}{3}$bài 15:a) ($\dfrac{-2}{3}$)9 : x = ($\dfrac{-2}{3}$)b) x : ($\dfrac{4}{9}$)5 = ($\dfrac{4}{9}$)4c) (x + 4)3 = -125d) (10 - 5x)3 = 64e) (4x + 5)2 = 81Bài 16:a) 4 - $1\dfrac{2}{5}$ - $\dfrac{8}{3}$b) -0,6 - $\dfrac{-4}{9}$ - $\dfrac{16}{15}$c) $-\dfrac{15}{4}$ . ($\dfrac{-7}{15}$) . ($-2\dfrac{2}{5}$Gi ải gấp giúp...

HT

Ha Thù

11 tháng 9 2023

#Toán lớp 7

3

VN

Võ Ngọc Phương

VIP

11 tháng 9 2023

Bài 4:

a) $\dfrac{4}{3}+\left(1,25-x\right)=2,25$

$1,25-x=2,25-\dfrac{4}{3}=\dfrac{9}{4}-\dfrac{4}{3}$

$1,25-x=\dfrac{11}{12}$

$x=1,25-\dfrac{11}{12}=\dfrac{5}{4}-\dfrac{11}{12}$

$x=\dfrac{1}{3}$

b) $\dfrac{17}{6}-\left(x-\dfrac{7}{6}\right)=\dfrac{7}{4}$

$x-\dfrac{7}{6}=\dfrac{17}{6}-\dfrac{7}{4}=\dfrac{34}{12}-\dfrac{21}{12}$

$x-\dfrac{7}{6}=\dfrac{13}{12}$

$x=\dfrac{13}{12}+\dfrac{7}{6}=\dfrac{13}{12}+\dfrac{14}{12}$

$x=\dfrac{27}{12}=\dfrac{9}{4}$

c) $4-\left(2x+1\right)=3-\dfrac{1}{3}=\dfrac{9}{3}-\dfrac{1}{3}$

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

$2x+1=\dfrac{8}{3}+4=\dfrac{8}{3}+\dfrac{12}{3}$

$2x+1=\dfrac{20}{3}$

$2x=\dfrac{20}{3}-1=\dfrac{20}{3}-\dfrac{3}{3}$

$2x=\dfrac{17}{3}$

$x=\dfrac{17}{3}.\dfrac{1}{2}=\dfrac{17}{6}$

Bài 15:

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

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

$=>x=\left(\dfrac{-2}{3}\right)^8$

b) $x:\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^4$

$x=\left(\dfrac{4}{9}\right)^4.\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^{4+5}$

$=>x=\left(\dfrac{4}{9}\right)^9$

c) $\left(x+4\right)^3=-125$

$\left(x+4\right)^3=\left(-5\right)^3$

$=>x+4=-5$

$x=-5-4$

$=>x=-9$

d) $\left(10-5x\right)^3=64$

$\left(10-5x\right)^3=4^3$

$=>10-5x=4$

$5x=10-4$

$5x=6$

$=>x=\dfrac{6}{5}$

e) $\left(4x+5\right)^2=81$

$\Leftrightarrow\left[{}\begin{matrix}\left(4x+5\right)^2=\left(-9\right)^2\\\left(4x+5\right)^2=9^2\end{matrix}\right.$

$\Leftrightarrow\left[{}\begin{matrix}4x+5=-9\\4x+5=9\end{matrix}\right.$

$\Leftrightarrow\left[{}\begin{matrix}4x=-14\\4x=4\end{matrix}\right.$

$\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-14}{4}\\x=1\end{matrix}\right.$

Bài 16:

a) $4-1\dfrac{2}{5}-\dfrac{8}{3}$

$=4-\dfrac{7}{5}-\dfrac{8}{3}$

$=\dfrac{60-21-40}{15}=\dfrac{-1}{15}$

b) $-0,6-\dfrac{-4}{9}-\dfrac{16}{15}$

$=\dfrac{-3}{5}+\dfrac{4}{9}-\dfrac{16}{15}$

$=\dfrac{\left(-27\right)+20-48}{45}=\dfrac{-55}{45}=\dfrac{-11}{9}$

c) $-\dfrac{15}{4}.\left(\dfrac{-7}{15}\right).\left(-2\dfrac{2}{5}\right)$

$=\dfrac{7}{4}.\dfrac{-12}{5}$

$=\dfrac{-21}{5}$

$#Wendy.Dang$

HT

Ha Thù

11 tháng 9 2023

Uh, chừa sau k dám học muộn nx

XT

Xuân Tuyền Đặng

28 tháng 3 2022

...

#Toán lớp 5

5

TH

Trần Hiếu Anh

28 tháng 3 2022

Hơi choáng

Đúng(4)

ZT

Zero Two

28 tháng 3 2022

Bạn đăng 2 câu 1 lần đc ko

Đúng(3)

CN

Chi Nghiêm

20 tháng 9 2023

$a,\dfrac{15-x}{14}=\dfrac{5}{7}$

$b,\dfrac{x}{9}=\dfrac{17}{3}$

$c,15-\dfrac{x}{2}=\dfrac{3}{7}$

Tìm x

#Toán lớp 5

2

DD

Di Di

20 tháng 9 2023

$\dfrac{15-x}{14}=\dfrac{5}{7}\\ \left(15-x\right)\times7=5\times14\\ \left(15-x\right)\times7=70\\ 15-x=70:7\\ 15-x=10\\ x=15-10\\ x=5$

__

$\dfrac{x}{9}=\dfrac{17}{3}\\ x\times3=17\times9\\ x\times3=153\\ x=153:3\\ x=51$

__

$15-\dfrac{x}{2}=\dfrac{3}{7}\\ \dfrac{x}{2}=15-\dfrac{3}{7}\\ \dfrac{x}{2}=\dfrac{102}{7}\\ x\times7=102\times2\\ x\times7=204\\ x=204:7\\ x=\dfrac{204}{7}$

CN

Chi Nghiêm

20 tháng 9 2023

???