Question

What is the value of the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4?

Answer 1

-80

Explanation:

2x^2 + 3xy - 4y^2

x = 2 | y = - 4

2(2)^2 + 3(2)(-4) - 4(-4)^2

2 * 4 + 3(2)(-4) - 4 * 16

8 - 24 - 64

-80