Question

resolva a função y=x2-x-20

Answer 1

x²-x-20=0
∆=b²-4ac
∆=(-1)²-4.1.(-20)
∆=1+80
∆=81
x=-b±√∆/2a
x=-(-1)-9/2.1
x=1-9/2
x=-8/2
x=-4
x=-(-1)+9/2.1
x=1+9/2
x=10/2
x=5
S={{-4, 5)}

Answer 2

y=x²—x—20
x²—x—20=0
☆=b²—4ac
☆=(1)²—4(1)(-20)
☆=1+80
☆=81

—b±√☆
————=X 1,2
2a


1)
1+√81/2.1
1+9/2
10/2
x=5

2)
1—√81/2.1
1—9/2
—8/2
x=—4

.Espero ter ajudado!!!