algebra
posted by T .
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

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.