15a - 25b + 20 = 5 (3a - 5b + 4)
5(3a - 5b + 4)
a2+9a+20 = (a+4)(a+5) when factored
m2 + 9m + 20 = (m + 5) (m + 4)
20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 + 20 = 400.
(x + 5) (x - 4)
2+2+2+10+5+5+5+20+20+20+20+20+20=151
5(3a - 5b + 4)
Factor completely and check mentally 10a^2+20a
a2+9a+20 = (a+4)(a+5) when factored
(x + 10)(x + 2)
5(4x + 9)
(3x + 5)(3x^2 + 4)
5(n2 + 2n + 4)
(x+6)(X+20)
x2 + x - 20 = (x + 5)(x - 4).
m2 + 9m + 20 = (m + 5) (m + 4)
(y + 5)(y - 4)
(3x - 5)(x + 4)