Question

[Nguyễn Thuy Lan]

Bài 1

a,(x-2/3)mũ 2=25/36

b,(3/4-x)mũ 3=-8

Answer 1

[Dương Lam Hàng]

a) \(\left(x-\frac{2}{3}\right)^2=\frac{25}{36}\)

\(\Rightarrow x-\frac{2}{3}=\pm\frac{5}{6}\)

Nếu \(x-\frac{2}{3}=\frac{5}{6}\Rightarrow x=\frac{5}{6}+\frac{2}{3}=\frac{3}{2}\)

Nếu \(x-\frac{2}{3}=\frac{-5}{6}\Rightarrow x=\frac{-5}{6}+\frac{2}{3}=\frac{-1}{6}\)

Vậy \(x=\left\{-\frac{1}{6};\frac{3}{2}\right\}\)

b) \(\left(\frac{3}{4}-x\right)^3=-8\)

Mà \(\left(-2\right)^2=-8\)

\(\Rightarrow\frac{3}{4}-x=-2\Rightarrow x=\frac{3}{4}-\left(-2\right)=\frac{3}{4}+2=\frac{11}{4}\)

Vậy \(x=\left\{\frac{11}{4}\right\}\)