Question

Pfr me ajudem!! -> (x+4).(x-1) = 5x+20

Answer 1

(x+4).(x-1) = 5x+20
x²-x+4x-4=5x+20
x²+3x-5x-4-20=0
x²-2x-24=0
a=1
b=-2
c=-24

Δ = b² - 4.a.c
Δ = (-2)² - 4 . 1 .(-24)
Δ = 4 + 96
Δ = 100

x = - b ± √Δ / 2a
x = - (-2) ± √100 / 2.1
x = 2 ± 10 / 2
x' = 2+10/2
x' =12/2
x'=6

x'' =2-10/2
x'' = -8/2
x'' = -4

S{-4, 6}