Question

( 1/ 3 x + 1/2 ) ²  = 4 / 81 

Answer 1

\(\left(\frac{1}{3}x+\frac{1}{2}\right)^2=\frac{4}{81}\)

\(\left(\frac{1}{3}x+\frac{1}{2}\right)^2=\left(\frac{2}{9}\right)^2=\left(\frac{-2}{9}\right)^2\)

=> \(\orbr{\begin{cases}\frac{1}{3}x+\frac{1}{2}=\frac{2}{9}\\\frac{1}{3}x+\frac{1}{2}=\frac{-2}{9}\end{cases}}\)=> \(\orbr{\begin{cases}\frac{1}{3}x=\frac{-5}{18}\\\frac{1}{3}x=\frac{-13}{18}\end{cases}}\)=> \(\orbr{\begin{cases}x=\frac{-5}{6}\\x=\frac{-13}{6}\end{cases}}\)

Vậy \(x\in\left\{\frac{-5}{6};\frac{-13}{6}\right\}\)

Answer 2

Nhầm toán lp 7 

Answer 3

(1/3x + 1/2)² = (2/9)²

1/3x+1/2 = 2/9

1/3x = -5/18

x= -5/6