1. p(7q+6r)+(q-r)(-5p)
2. (x+2)^2+(x-2)^2
3. 25u^2-(5u+3)(5u-3)
4. t(5-2t)-(3t-1)(4t)
5. (7cd-3)(2cd+5)
6. (2xy+3z)(4xy-z)
7. (a^2+2a+3)(a+2)
8. (2b^2-3b+1)(4b-1)
9. (2t-1)(t-2)(3t+1)
10. (x^2-x+1)(x^2+x+1)