1) (a + 9)^2 + 2a(a + 9)= (a + 9)(a + 9) + 2a(a + 9)= (a + 9)(a + 9 + 2a)= (a + 9)(a + 2a + 9)= (a + 9)(3a + 9)
2) 30x^80 + 80x^30= 10x^30(3x^50 + 8)
3) x^2(b - 2) + y(2 - b)= x^2(b - 2) - y(b - 2)= (x^2 - y)(b - 2)
4) 2m(a - 3) - 5c(3 - a)= 2m(a - 3) + 5c(a - 3)= (2m + 5c)(a - 3)
1) (a + 9)^2 + 2a(a + 9)
= (a + 9)(a + 9) + 2a(a + 9)
= (a + 9)(a + 9 + 2a)
= (a + 9)(a + 2a + 9)
= (a + 9)(3a + 9)
2) 30x^80 + 80x^30
= 10x^30(3x^50 + 8)
3) x^2(b - 2) + y(2 - b)
= x^2(b - 2) - y(b - 2)
= (x^2 - y)(b - 2)
4) 2m(a - 3) - 5c(3 - a)
= 2m(a - 3) + 5c(a - 3)
= (2m + 5c)(a - 3)