Ta có: \(\frac{5,7}{0,35}=\frac{\left(-x\right)}{0,45}\)

\(\Rightarrow5,7.0,45:0,35=\left(-x\right)\)

\(\Rightarrow2,565:0,35=\left(-x\right)\)

\(\Rightarrow\left(-x\right)=7,3\left(285714\right)\)

Vậy x = -7,3 (285714)

5,7/0,35=(-x)/0,45

=>5,7x0,45=0,35x(-x)

=>0,35x(-x)=2,565

=>(-x)=2,565:0,35

=> x= 2,565: (-0,35)

=>x gần bằng 7,35

-7/23/30

a) \(\frac{x}{7}=\frac{18}{14}\)

\(\frac{x}{7}=\frac{9}{7}\)

\(\Rightarrow x=9\)

b) \(6:x=1\frac{3}{4}:5\)

\(6:x=\frac{7}{4}.\frac{1}{5}\)

\(6:x=\frac{7}{20}\)

\(x=6:\frac{7}{20}\)

\(x=\frac{120}{7}\)

vay \(x=\frac{120}{7}\)

c) \(\frac{5,7}{0,35}=\frac{-x}{0,45}\)

\(\Rightarrow-0,35x=5,7.0,45\)

\(\Rightarrow-0,35x=2,565\)

\(\Rightarrow x=\frac{-2,565}{0,35}\)

\(\Rightarrow x=\frac{-513}{70}\)

vay \(x=\frac{-513}{70}\)

a)\(\dfrac{x}{7}=\dfrac{18}{14}\)

\(\Rightarrow x=\dfrac{7.18}{14}=9\)

b)\(6:x=1\dfrac{3}{4}\)

\(\Leftrightarrow\dfrac{6}{x}=\dfrac{7}{4}\)

\(\Rightarrow x=\dfrac{6.4}{7}=\dfrac{24}{7}\)

c)5,7:0,35=(-x):0,45

\(\Leftrightarrow\dfrac{114}{7}=\dfrac{-x}{0,45}\)

\(\Rightarrow\left(-x\right)=\dfrac{114.0,45}{7}=\dfrac{-513}{70}\)

\(a,x=\dfrac{18.7}{14}\)

\(x=\dfrac{8}{2}=4\)

\(b,\)\(x=6.5:1\dfrac{3}{4}\)

\(x=30:\dfrac{7}{4}\)

\(x=30.\dfrac{4}{7}=\dfrac{120}{7}\)

\(c,-x=\)\(\dfrac{5,7.0,45}{0,35}\)

\(-x=\)\(\dfrac{2,565}{0,35}\)

\(x=\dfrac{-2,565}{0,35}\)

a)\(\dfrac{x}{7}=\dfrac{18}{14}\) b) 6:x=\(1\dfrac{3}{4}\):5 c) 5,7 : 0,35= -x: 0,45

\(\Rightarrow\) x.14= 18.7 \(\Rightarrow\) 6:x=\(\dfrac{7}{20}\) \(\Rightarrow\)\(\dfrac{114}{7}=\dfrac{-x}{0,45}\)

\(\Rightarrow\)x.14=126 \(\Rightarrow\)x=\(\dfrac{10}{21}\) \(\Rightarrow53,1=\left(-x\right).7\)

\(\Rightarrow\)x=9 \(\Rightarrow x=7,3\)

CHÚC BẠN HỌC TỐT

a, \(\dfrac{x}{7}\)=\(\dfrac{18}{14}\)

\(x.14=7.18\)

\(x.14=126\)

\(\Rightarrow x=9\)

b,\(6:x=1^3_4:5\)

\(6:x=\dfrac{7}{20}\)

\(x=\dfrac{7}{120}\)

a)x=18*7/14=9

b)x=6.5/(7/4)=120/7

c)-x=5,7*0,45/0,35=513/70

Ta có :

\(\frac{5,7}{3,5}=-\frac{x}{0,45}\)

\(\Rightarrow x=\frac{5,7}{3,5}.\left(-0,45\right)\)

\(\Rightarrow x=-\frac{513}{700}\)

Vậy x = - 513 / 700

\(5,7:0,35=\left(-x\right):0,45\)

\(\Leftrightarrow-x=\frac{5,7\cdot0,45}{0,25}=10.26\)

\(\Leftrightarrow x=-10,26\)

a) \(\frac{x}{7}=\frac{18}{14}\)

\(\Rightarrow\frac{x}{7}=\frac{9}{7}\)

\(\Rightarrow x=7\)

Vậy x=7

b)\(6:x=1\frac{3}{4}:5\)

\(\frac{6}{x}=\frac{7}{4}:5\)

\(\frac{6}{x}=\frac{7}{20}\)

\(\Rightarrow6.20=7x\)

\(\Rightarrow120=7.x\)

\(\Rightarrow x=\frac{120}{7}\)

Vậy \(x=\frac{120}{7}\)

a) Ta có :

\(x\)/7 = 18/14

=> \(x\) = (7 x 18)/14

x= 9

b) Ta có:

6 : \(x\)= 1(3/4) : 5

=> \(x\)= (6 x 5)/1(3/4)

= \(\frac{30}{\frac{7}{4}}\)

c) Ta có:

5,7 : 0,35 = -\(x\):0,45

=> -\(x\)= (5,7 x 0,45)/ 0,35

\(x\)=5130/7

\(\frac{7}{x-1}=\frac{x+1}{9}\)

\(\Rightarrow\left(x-1\right)\left(x+1\right)=7.9\)

\(\Rightarrow x^2-1=63\)

\(\Rightarrow x^2=64\)

\(\Rightarrow\orbr{\begin{cases}x=8\\x=-8\end{cases}}\)

\(\frac{x-1}{x+2}=\frac{x-2}{x+3}\)

\(\Rightarrow\left(x-1\right)\left(x+3\right)=\left(x+2\right)\left(x-2\right)\)

\(\Rightarrow x^2+2x-3=x^2-4\)

\(\Rightarrow2x-3=4\)

\(\Rightarrow2x=7\)

\(\Rightarrow x=\frac{7}{2}\)