Question

\(a.\frac{x-3}{5}=\frac{4}{9}\)

b.\(\left(x-\frac{1}{4}\right)^2:^{ }3^2=81\)

giải giúp mình nhé nhanh nhất mình chọn ahihi

Answer 1

a) \(\frac{x-3}{5}=\frac{4}{9}\)

=> ( x - 3) . 9 = 20

=> 9x - 27 = 20

=> 9x = 47

=> x = \(\frac{47}{9}\)

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

\(\Rightarrow\left(x-\frac{1}{3}\right)^2:9=81\)

\(\Rightarrow\left(x-\frac{1}{4}\right)^2=729\)

\(\Rightarrow x-\frac{1}{4}=27\) hoặc \(x-\frac{1}{4}=-27\)

+) \(x-\frac{1}{4}=27\Rightarrow x=\frac{109}{4}\)

+) \(x-\frac{1}{4}=-27\Rightarrow x=\frac{-107}{4}\)