Question

quanto que e x elevado al quadrado +x-20=0

Answer 1

x(2)+x-20=0
a=1 b=1 c=-20

/\=b(2)-4.ac
/\=1(2)-4.1.(-20)
/\=1+80
/\=81

x=-b+- {raiz de /\}/2.a
x=-1+- {raiz de 81}/2.1
x=-1+-9/2
x'=-1+9/2=8/2=4
x''=-1-9/2=-10/2=-5

S={4,-5}