Question

How do you factor `-375a^3 + 648`?

Answer 1

`3(6-5a)(36+30a +25a^2)`

Explanation:

To factorise, we can try to put into the shape of difference of cubes, to see if this can help. Accordingly,

`-375a^3 +648 = 3( 216- 125a^3)`

=`3(6^3 - 5^3 a^3)`

= `3(6-5a)(6^2 +6*5a +5^2a^2)`

=`3(6-5a)(36+30a +25a^2)`