1) 5cd³-15c³d=5сd·(d²-5c²)= 5cd·(d-√5·c)(d+√5·c)
2) 3q(p+q)-(p+q)²= (p+q)(3q-p-q)=(p+q)(2q-p)
3) a²+ab-7a-7b= a(a+b) - 7(a+b)=(a+b)(a-7)
4) 6pq+3q²+2pq= ?
5) x² - 121= (х - 11)(х + 11)
6)49m² - 4= (7m - 2) ( 7 m + 2)
7) 8x²-2y²=2·(4x²-y²)=2·(2x-y)(2x+y)