Question

Solve the equation 9|9-8x|=2x+3 show work.

Answer 1

As you already know, an absolute value expression is a piece-wise in effect.

$\bf 9|9-8x|=2x+3\implies |9-8x|=\cfrac{2x+3}{9}\\\\\\ \begin{cases} +(9-8x)=\cfrac{2x+3}{9}\\\\ -(9-8x)=\cfrac{2x+3}{9} \end{cases}\\\\ -------------------------------\\\\ 9-8x=\cfrac{2x+3}{9}\implies 81-72x=2x+3\implies 78=74x \\\\\\ \cfrac{78}{74}=x\implies \cfrac{39}{37}=x\\\\ -------------------------------\\\\ -(9-8x)=\cfrac{2x+3}{9}\implies -9+8x=\cfrac{2x+3}{9} \\\\\\ -81+72x=2x+3\implies 70x=84\implies x=\cfrac{84}{70}\implies x=\cfrac{6}{5}$