Question

Factor 15a3 + 40a

Answer 1

Try to find as many common factors as possible.
First find the c.f. of 15 and 40,
Then find those of a³ and a,

In the end, put the common factors outside brackets, like in: p(q+r).

Answer 2

To do it, factor 15 and 40:

15 = 3 * 5
40 = 5 * 8 (=5 * 2 * 2 * 2),

So 5 is the common factor of 15 and 40.

Now a³ and a:

a³ = a * a * a
a = a * 1,

so a is common factor.

Now you put everything together!