Question

resolva no formato ax²+bx=0
a)x²+5x=0
b)3x²-9x=0
c)5x²+6x=0
d)3x+18x=0

Answer 1

a) x^2+5x=0
delta=b^2-4ac
delta=5^2-4.1.0
delta=25-0
delta=25
x=-b-/+ raiz de delta/2a
x=-5-5/2.1
x=-10/2
x=-5
x=-5+5/2.1
x=0/2
x=0
b) 3x^2-9x=0
delta=b^2-4ac
delta=(-9)^2-4.3.0
delta=81-0
delta=81
x=-b-/+ raiz de delta/2a
x=-(-9)-9/2.3
x=9-9/6
x=0/6
x=0
x=-(-9)+9/2.3
x=9+9/6
x=18/6
x=3
c) 5x^2+6x=0
delta=b^2-4ac
delta=6^2-4.5.0
delta=36-0
delta=36
x=-b-/+ raiz de delta/2a
x=-6-6/2.5
x=-12/10 (:2)
x=-6/5
x=-6+6/2.5
x=0/10
x=0
d) 3x^2+18x=0
delta=b^2-4ac
delta=18^2-4.3.0
delta=324-0
delta=324
x=-b-/+ raiz de delta/2a
x=-18-18/2.3
x=-36/6
x=-6
x=-18+18/2.3
x=0/6
x=0