Question

Quanto é:
x² + 2x = 8
???

Answer 1

espero ter ajudado, deixe um like pfv

Answer 2

x² + 2x = 8

x² + 2x - 8=0

a=1
b=2
c= -8

Δ=b² -4ac
Δ=2² -4(1)(-8)
Δ=4+32
Δ=36

$x= \frac{-b\pm \sqrt{\Delta} }{2a} =~~ \frac{-2\pm \sqrt{36} }{2} =~~ \frac{-2\pm6}{2} \\ \\ x'= \frac{-2+6}{2} = \frac{4}{2} =2 \\ \\ x"= \frac{-2-6}{2} =- \frac{8}{2} =-4 \\ \\ S=\{-4,2\}$