Get the algebraic expressions in the following cases using variables, constants and arithmetic operations.

- Subtraction of z from y.
- One-half of the sum of numbers x and y.
- The number z multiplied by itself
- One-fourth of the product of numbers p and q.
- Numbers x and y both squared and added.
- Number 5 added to three times the product of numbers m and n.
- Product of numbers y and z subtracted from 10.
- Sum of numbers a and b subtracted from their product.