Maths!!!!

Adding and Subtracting Rational Expression~~

1. (5x/x^2-x-6) - (4/x^2+4x+4)

2. (5/x^2-36) + (9/x^2+5x-6)

3. (2x/x^2-x-2) - (5x/x^2-3x+2)

4. (3x/x^2-2x-3) - (5/x^2+4x+3)

5. (-3x/x^2-9) + (4/2x+6)

幫幫我唔該!!!