Question

(X-10)•(2x+4)=x2+2•(12x-218)

Answer 1

2x² +4x -20x - 40= x² + 24x - 436
passa tudo pro um lado so
2x² - x² + 4x - 20x - 24x - 40 + 436 = 0
x² - 40x + 396 = 0
a=1
b= - 40
c= 396
Δ= b² - 4ac
Δ= (-40)² - 4.1.396
Δ= 1600 - 1584
Δ = 16
$x = \frac{-b+- \sqrt{Δ} }{2a}$
$x = \frac{- (-40) +- \sqrt{16} }{2.1}$
$x = \frac{ 40 +- 4 }{2}$
$x' = \frac{ 40 + 4 }{2}$
$x' = \frac{ 44 }{2}$
x' = 22
$x" = \frac{ 40 - 4 }{2}$
$x" = \frac{ 36 }{2}$
x" = 18