Question

X elevado a 2 mais 5x igual a zero

Answer 1

x²+5x=0
a=1 b=5

∆=b²-4ac
∆=5²-4*1*0
∆=25

x=-b±√∆ /2a
x1=-5+√25 /2*1
x1=-5+5/2
x1=0

x2=-5-5/2
x2=-10/2
x2=-5

S={0;-5}

Answer 2

$x^2+5x=0 \\ x(x+5)=0 \\ \\ x'=0 \\ x"=x+5=0 \\ x"=-5$