Question

1) Resolva as equações abaixo:
a) x² - 64 = 0
b) -16x² + 49 = 0
c) x² - 7x = 0
d) x(x + 2) = 5x

Answer 1

a) x^2-64=0
x^2=0+64
x^2=64
x= raiz de 64
x=-/+8
b) -16x^2+49=0
delta=b^2-4ac
delta=0^2-4.(-16).0
delta=0+0
delta=0
x=-b-/+ raiz de delta/2a
x=-0-0/2.(-16)
x=0/-32
x=0
c) x^2-7x=0
delta=b^2-4ac
delta=(-7)^2-4.1.0
delta=49-0
delta=49
x=-b-/+ raiz de delta/2a
x=-(-7)-7/2.1
x=7-7/2
x=0/2
x=0
x=-(-7)+7/2.1
x=7+7/2
x=14/2
x=7
d) x(x+2)=5x
x^2+2x=5x
x^2+2x-5x
x^2-3x=0
delta=b^2-4ac
delta=(-3)^2-4.1.0
delta=9-0
delta=9
x=-b-/+ raiz de delta/2a
x=-(-3)-3/2.1
x=3-3/2
x=0/2
x=0
x=-(-3)+3/2.1
x=3+3/2
x=6/2
x=3