Question

y=X ao quadrado -6x +8

Answer 1

y = x²
-6x +8 = 0
-6x= -8
x = 8/-6 
x = 1,3
y = x²
y = (1,3)²
y = 1,69  seria isso ?

Answer 2

∆=6²-4•1•8
∆=36-32
∆=4

x=6+4/2=5
x¹=6-2/2=2
y{5 e 2