What is the value of the expression 2x to the 2nd power + 3xy -4y to the 2nd power when x = 2 and y = -4? please show how to solve this

Answer 1

I assume your problem is this:

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

Note: you can use ^ to mean raised to the power of some value; for example x^2 means x raised to the power of 2 (or x squared).

Substitute 2 for x and -4 for y to evaluate the expression.

I hope this will help get you started.