Question

Resolva as seguintes equações do 2 grau x(x-3)28 ,(x+5)elevando a 2=25 e (x-2)elevando a 2=4-9x

Answer 1

x(x-3)=28
x^2-3x=28
x^2-3x-28=0
delta=b^2-4ac
delta=(-3)^2-4.1.(-28)
delta=9+112
delta=121
x=-b-/+ raiz de delta/2a
x=-(-3)-11/2.1
x=3-11/2
x=-8/2
x=-4
x=-(-3)+11/2.1
x=3+11/2
x=14/2
x=7
(x+5)^2=25
x^2+2.x.5+5^2=25
x^2+10x+25-25
x^2+10x=0
x(x+10)=0
x=0
x+10=0
x=0-10
x=-10
(x-2)^2=4-9x
x^2-2.x.2+(-2)=4-9x
x^2-4x-2=4-9x
x^2-4x+9x-2-4
x^2+5x-6=0
delta=b^2-4ac
delta=5^2-4.1.(-6)
delta=25+24
delta=49
x=-b-/+ raiz de delta/2a
x=-5-7/2.1
x=-12/2
x=-6
x=-5+7/2.1
x=2/2
x=1