1. expand (3x2+2y)(5x2+4y)
2. expand (2x2+6y)(4x2−2y)
3. expand (5x2−3y)(2x2+5y)
4. expand (8x2+8y)(3x2+8y)
5. expand (9x2+8y)(8x2−2y)
6. expand (4x2−4y)(7x2+8y)
7. expand (7x2+9y)(4x2+8y)
8. expand (3x2−3y)(2x2+7y)
9. expand (3x2+5y)(2x2+10y)
10. expand (3x2−2y)(7x2+9y)