Question

Seja a função y=x²-7x+10.Quais são os valores de x para y=18?

Answer 1

y=x^2-7x+10
18=x^2-7x+10
x^2-7x+10-18
x^2-7x-8=0
delta=b^2-4ac
delta=(-7)^2-4.1.(-8)
delta=49+32
delta=81
x=-b-/+ raiz de delta/2a
x=-(-7)-9/2.1
x=7-9/2
x=-2/2
x=-1
x=-(-7)+9/2.1
x=7+9/2
x=16/2
x=8