Question

x(x+4)+x(x+2)=x²+12 pode resolver pra mim por favor

Answer 1

x(x+4)+x(x+2)=x²+12

x² + 4x + x² +2x = x² + 12
x² + x² - x² + 4x +2x = 12
x² + 6x - 12 = 0

a = 1
b = 6
c = -12

Δ = b² -4 .a .c

Δ = 6² -4 . 1 . (-12)
Δ = 36  + 48
Δ = 84 

-b +- √Δ   / 2 .a

-6 +- √84   /2 . 1
-6 +- 9,16515138991   /2

x' = -6 + 9,16515138991  / 2
x' = 3,16515138991 / 2
x' = 1,58257569496   ou  1,58

x'' = -6 - 9,16515138991  / 2
x" = -15,1651513899 / 2
x" = -7,58257569495  ou -7,58

Resposta decima:  S { 1,58   e   -7,58 }