Question

resolva as equaçoes do 2grau a) 2(y+6)=y(y-2) b) x(x+3)=40 c) 2(x+1)²+7=1-3x d) m²/4-1=5m/8-5/4 e) 2y-2/5+1/10-y(y+1)/5=-3/10 é urgente me ajudem pfv

Answer 1

a) 2(y+6)=y(y-2)
2y+12=y^2-2y
-y^2+2y+2y+12
-y^2+4y+12=0
delta=b^2-4ac
delta=4^2-4.(-1).12
delta=16+48
delta=64
x=-b-/+ raiz de delta/2a
x=-4-8/2. (-1)
x=-12/-2
x=6
x=-4+8/2.(-1)
x=4/(-2)
x=-2
b) x(x+3)=40
x^2+3x=40
x^2+3x-40=0
delta=b^2-4ac
delta=3^2-4.1.(-40)
delta=9+160
delta=169
x=-b-/+ raiz de delta/2a
x=-3-13/2.1
x=-16/2
x=-8
x=-3+13/2.1
x=10/2
x=5
c) 2(x+1)^2+7=1-3x
2(x)^2+2.x.1+1^2+7=1-3x
2x^2+2x+1+7=1-3x
2x^2+2x+8=1-3x
2x^2+2x+3x+8-1
2x^2+5x+7=0
delta=b^2-4ac
delta=5^2-4.2.7
delta=25-56
delta=-31
delta negativo não há raízes reais.
d) m^2/4-1=5m/8-5/4
8m^2-5m^2/4m^2=20m-5m
32m^2-5m^2=20m-5m
27m^2=15m
27m^2-15m=0
delta=b^2-4ac
delta=(-15)^2-4.27.0
delta=225-0
delta=225
x=-b-/+ raiz de delta/2a
x=-(-15)-16/2.1
x=15-16/2
x=-1/2
x=-(-15)+16/2.1
x=15+16/2
x=31/2