Question

Resolvendo a equação x2 + x -7=5, obtemos:
a) x= -3 e x=4
b)x=3 e x=4
c)x=5 e x=7
d)x=-5 e x=7
e)x=1 e x=4

Answer 1

x²+x-7=5
x²+x-7-5=0
x²+x -12=0
∆=1²-4.1.(-12)
∆=1+48
∆=49
x= -1 ±√49/2.1
x= -1±7/2
x1= -1+7/2= 6/2=3
x2= -1-7/2= -8/2= -4