Question

Tìm x

a)\(\left(x-2,5\right)^2\) = \(\frac{4}{9}\)

b)\(\left(2x+\frac{1}{3}\right)^3=\frac{-8}{27}\)

c) \(\frac{2}{3}.3^{x+1}-7.3^x=-405\)

d) \(\left(\frac{3}{5}-\frac{2}{3}x\right)^2=\frac{-64}{125}\)
Giúp mình

Answer 1

a)\(\left(x-2,5\right)^2=\frac{4}{9}\\ \left(x-\frac{5}{2}\right)^2=\left(\pm\frac{2}{3}\right)^2\\\Leftrightarrow\left\{{}\begin{matrix}x-\frac{5}{2}=\frac{2}{3}\\x-\frac{5}{2}=\frac{-2}{3}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\frac{19}{6}\\x=\frac{11}{6}\end{matrix}\right. \)

vậy....

b)\(\left(2x+\frac{1}{3}\right)^3=\frac{-8}{27}\\ \left(2x+\frac{1}{3}\right)^3=\left(\frac{-2}{3}\right)^3\\ 2x+\frac{1}{3}=\frac{-2}{3}\\ x=\frac{-1}{2}\)

vậy...