Answer:
4y^3 + 4x^2 - 2
Step-by-step explanation:
Sort out these terms following powers of x and y:
First, y terms:
6y^3 - 2y^3 => 4y^3
Next, constants:
7 - 7 - 2 => -2
Next, x^2 terms:
6x^2 - 2x^2 => 4x^2
Now write out the modified expression, using the "combined terms" results given above:
4y^3 + 4x^2 - 2
