Explicação passo-a-passo:
x²-7=x + 5x
x²-x-5x-7=0
x²-6x-7=0
a=1
b=-6
c=-7
∆=b²-4ac
∆=(-6)²-4×1×-7
∆=36+28
∆=64
-b±√∆/2a
6±√64/2×1
6±8/2
x¹=6+8/2=14/2=7
x²=6-8/2=-2/2=-1
x²+11x= 16x-6x
x²+11x-16x+6x=0
x²-5x+6x=0
x²+x=0
x(x+1)=0
x+1=0
x=0-1
x=-1
s={0,-1}
