Need help with homework problems.

Simplify fractions
5x + 2y/35x + 14y
x^2 - 5x - 14/2^x2 - x- 10

Multiply
x^2 - x - 20.x^2 + 7^x + 10/x^2 - 3x - 10. x^2 + 4x - 5

4x^2