How would you figure out 2x^2+3xy-4y^2 when x = 2 and y = -4

Replace every x with 2 and every y with -4: 2(2)^2 + 3(2)(-4) - 4(-4)^2

Simplify: 2(4) + 3(-8) - 4(16)

Simplify: 8 - 24 - 64

Simplify: -80

Plyg x = 2 and y = -4 into the expression.

2(2)^2 + 3(2)(-4) - 4(-4)^2
2(4) + 3(-8) - 4(16)
8 - 24 - 64
-80