1) 7х^2-28х-6х+х^2=8х^2-34х =2х(4х-17)
2) 20а^2b+15ab^2-20a^2b+40a^2=15ab^2+40a^2 =5a(3b^2+8a)
3) 2x^2y-11xy^2-x^2y-14xy^2 =x^2y-25xy^2=xy(x-25y)
4) 20c^4-15c^3-16c^4+24c^2 =4c^4-15c^3+24c^2 =c^2(4c^2-15c+24)
1) 7х^2-28х-6х+х^2=8х^2-34х =2х(4х-17)
2) 20а^2b+15ab^2-20a^2b+40a^2=15ab^2+40a^2 =5a(3b^2+8a)
3) 2x^2y-11xy^2-x^2y-14xy^2 =x^2y-25xy^2=xy(x-25y)
4) 20c^4-15c^3-16c^4+24c^2 =4c^4-15c^3+24c^2 =c^2(4c^2-15c+24)