Question

Me ajudem calcule as raizes das equações do segundo grau A-10x²+72x-64=0 B-2x²-90=8

Answer 1

a) 10x^2+72x-64=0
delta=b^2-4.a.c
delta=72^2-4.10.(-64)
delta=5184+2560
delta=7744
x=-b-/+ raiz de delta/2a
x=-72-88/2.10
x=-160/20
x=-8
x=-72+88/2.10
x=16/20 (:4)
x=4/5 b) 2x^2-90=8 2x^2-90-8 2x^2-98=0 2x^2=0+98 2x^2=98 X^2=98/2 X^2=49 X=-/+ raiz de 49 X=-/+ 7