Question

[ ( x.x+55)-31] .14 = 560

 

Answer 1

[(x.x + 55) - 31].14 = 560

x² + 55 - 31 = 560 : 14

x² + 24 = 40

x² = 40 - 24

x² = 16

x = 4 hoặc x = -4

Answer 2

\(\left[\left(x\cdot x+55\right)-31\right]\cdot14=560\)

=>\(\left(x^2+55-31\right)=40\)

=>\(x^2=16\)

=>\(\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)