Question

Equação do 2° grau
a)2x+3.(x²-5)=-x²-6=2x
b)5x²-60x=0

Answer 1

a) 2x+3(x^2-5)=-x^2-6=2x
2x+3x^2-15=-x^2-6=2x
2x+3x^2-15=-x^2-6-2x
3x^2+x^2+2x+2x-15
4x^2+4x-15=0
delta=b^2-4ac
delta=4^2-4.4.(-15)
delta=16+240
delta=256
x=-b-/+ raiz de delta/2a
x=-4-16/2.4
x=-20/8 (:4)
x=-5/2
x=-4+16/2.4
x=12/8 (:4)
x=3/2
b) 5x^2-60x=0
delta=b^2-4ac
delta=(-60)^2-4.5.0
delta=3600-0
delta=3600
x=-b-/+ raiz de delta/2a
x=-(-60)-60/2.5
x=60-60/10
x=0/10
x=0
x=-(-60)+60/2.5
x=60+60/10
x=120/10
x=12