a) 3/4x = 1

         x = 1 : 3/4

         x = 4/3

b) 4/7x = 9/8 - 0,125

    4/7x = 1

        x = 1 : 4/7

        x = 7/4

a)\(\frac{3}{4}\). x =1

             x=1:\(\frac{3}{4}\)

             x=      \(\frac{4}{3}\)

b)\(\frac{4}{7}\).x=\(\frac{9}{8}\)-0,125

\(\frac{4}{7}\).x=1,125-0,125

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

         x=1:\(\frac{4}{7}\)

         x=\(\frac{7}{4}\)

CHÚC BẠN HỌC GIỎI

K MÌNH NHÉ

a/

   3/4 . x = 1

  => x= 1: 3/4 = 4/3

b/

       4/7 .x = 9/8 -0,125 = 9/8 -1/8 = 1

   => x= 1 : 4/7 = 7/4

a/ 3/4x=1

x=1:3/4

x=4/3

b/ 4/7x=9/8-0,125

4/7x=1

x=1:4/7

x=7/4

3/ 4x=1 <=>x=1/4

4/7x=9/8-0,125 <=>7x=1<=>x=1/7

3/4x=1

<=>x=4/3

4/7x=9/8-0,125

<=>4/7x=9/8-1/8=8/8=1

<=>x=7/4

*4/7x=9/8.0,125 

4/7x=9/8.1/8

4/7x=9/64

x    =9/64:4/7

x    =9/64.7/4

x    =63/256

*x-25%=1/2

x-1/4.x  =1/2

x(1-1/4) =1/2

3/4.x     =1/2

x           =1/2:3/4

x           =1/2.4/3

x           =2/3

a) \(55-4x-4\left(-x+3\right)=6-2\left(-8-3x\right)\)

\(55-4x+4x-12=6+16+6x\)

\(43-6-16=6x\)

\(6x=21\)

\(x=3,5\)

b) \(-5\left(-2x-6\right)-9\left(4-7x\right)=51-3x+6\left(x-9\right)\)

\(10x+30-36+63x=51-3x+6x-54\)

\(73x-6=-3+3x\)

\(73x-3x=-3+6\)

\(70x=3\)

\(x=\frac{3}{70}\)

c) \(93+\left|6-3x\right|-39=231\)

\(\left|6-3x\right|+54=231\)

\(\left|6-3x\right|=177\)

\(\Rightarrow\orbr{\begin{cases}6-3x=177\\6-3x=-177\end{cases}}\Rightarrow\orbr{\begin{cases}3x=6-177\\3x=6+177\end{cases}}\Rightarrow\orbr{\begin{cases}3x=-171\\3x=183\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-57\\x=61\end{cases}}\)

a)       \(55-4x-4\left(-x+3\right)=6-2\left(-8-3x\right)\)

\(\Leftrightarrow\)\(55-4x+4x-12=6+16+6x\)

\(\Leftrightarrow\)\(6x+22=43\)

\(\Leftrightarrow\)\(6x=43-22=21\)

\(\Leftrightarrow\)\(x=21:6=3.5\)

Vậy...

Happy birthday to you, my friend !!!

a,    x = -4

b,    x = 1

c,    x = 1/3

a)x=-4

b)x=1

c)x=\(\frac{1}{3}\)1/3

kik cho mik rồi mik kik lại cho

\(1,\\ a,=7x^3-49x^2+21x\\ b,=x^2-x-42\\ c,=x^2-16x+64\\ d,=9x^2+12x+4\\ e,=x^2-16-25+10x-x^2=10x-41\\ 2,\\ a,\Rightarrow2\left(x-7\right)=19\\ \Rightarrow x-7=\dfrac{19}{2}\Rightarrow x=\dfrac{33}{2}\\ b,\Rightarrow4x^2-20x+25-4x^2+3x-2x=50\\ \Rightarrow-19x=25\Rightarrow x=-\dfrac{25}{19}\)