How do you factor the expression #r^3 - 3r^2 - 54r#?
1 Answer
Mar 4, 2016
Explanation:
#r^3 - 3r^2 - 54r = = r(r^2 - 3r - 54)#
#54 = 54 * 1 = 27 * 2 = 6 * 9# .
You can thus say that
#r^2 - 3r - 54 = r^2 + 6r - 9r - 54#
#r(r + 6) - 9(r + 6) = (r-9)(r+6)#
Therefore, the original expression can be factored as
#r * (r-9)(r+6)#
