Question

Tìm x khi

a) x : ( 2/9 - 1/5 ) = 8/16

b) ( x + 1/2 ) . ( x - 3/4 ) = 0

Answer 1

a> \(x:\left(\dfrac{2}{9}-\dfrac{1}{5}\right)=\dfrac{8}{16}\)

=> \(x:\left(\dfrac{10}{45}-\dfrac{9}{45}\right)=\dfrac{1}{2}\)

=> \(x:\dfrac{1}{45}=\dfrac{1}{2}\)

=> x=\(\dfrac{1}{45}.\dfrac{1}{2}\)

=> x= \(\dfrac{1}{90}\)

b > \(\left(x+\dfrac{1}{2}\right)\left(x-\dfrac{3}{4}\right)=0\)

=> \(\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\x-\dfrac{3}{4}=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{3}{4}\end{matrix}\right.\)