Question

(x-3).(10-2x)=0

 

Answer 1

\(\left[{}\begin{matrix}x-3=0\\10-2x=0\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=3\\x=5\end{matrix}\right.\)

Answer 2

(x-3).(10-2x)=0

(x-3).10 - (x-3).2x = 0

x10 - 3.10 - 2x² - 3.2x = 0 

x10 - 30 - 2x - 2x . 1x + 2x + 2x = 0

x(10 - 2 + 2 + 2) - 2x . 1x = 0

x12 - 2x . 1x = 0 

x(12 - 2) . 1x = 0

10x - 1x = 0

9x = 0

x = 0 : 9

x = 0