y=2x^2−4x
y=2x(x+2)
x=2 ==> y=16
x=-2 ==> y=0
x=3 ==> y=30
x=5 ==> 70
y=2x^2−4x*2x
y=2x^2(1-4)
y=2x^2*(-3)
x=2 ==> y=-24
x=-2 ==> y=-24
x=3 ==> y=-54
x=5 ==> y=-150
y=2x^2−4x
y=2x(x+2)
x=2 ==> y=16
x=-2 ==> y=0
x=3 ==> y=30
x=5 ==> 70
y=2x^2−4x*2x
y=2x^2(1-4)
y=2x^2*(-3)
x=2 ==> y=-24
x=-2 ==> y=-24
x=3 ==> y=-54
x=5 ==> y=-150