Simplify each expression. 1. (10x 5y) – (9x – 5y)
2. (–5m 3x) (–7m 10x) 5
3. (6a 5b 4c) (–6c 15b) (–8a)
4. (–8x 7y) 9y (–8x)
5. (3r 6t) (2r 7t) 4t (–3r)
6. (9h – 4j) – (7h – j)