9x +36
9(x+4)
x2 - 9
(x + 3)(x - 3)
6 & 8
2
r2 - 36
(r +6)(r-6)
5 & 10
5
4x2+10x
2x(2x+5)
x2 - 14x + 49
(x-7)(x-7)
4x2-9
(2x-3)(2x+3)
18 & 30
6
30 & 45
15
a2 - 10a + 25
(a - 5) (a - 5)
8 & 12 & 20
4