1. Expand and simplify 2b(3b + a) + 4a(5b + a)
2. Expand and simplify 5r(4r + s) − 3s(2r − 2s)
3. Expand and simplify a(7a + 10b) − b(8a − 2b)
4. Expand and simplify 2a(9a + 16b) − 4b(2a − 8b)
5. Expand and simplify x(3x + 20y) + 10y(4y − 2x)
6. Expand and simplify 30x(x − y) + 15y(2x + 3y)
7. Expand and simplify a2 (2a + 14b) + 5b(6a2 + 8b)
8. Expand and simplify 4a2 (3a + 12b) + 2b(7a2 + 9b)
back to: 
to: 
