1. Simplify the expression:

15x^2-x-2 / 3x^2-5x-2

2. Simplify the expression:

14x^2y^6z^9 / 7x^5y^4z^11

3. Simplify the expression:

3y^2+5yz+2z^2 / 2y^2+3yz+z^2

4