Question

factor: $18 - 81r^2$
a. $9r(18 - 81r^2)$
b. $9r(2 - 9r^3)$
c. $9(6r - 27r^2)$
d. $9(2 - 9r^2)$
reset selection

Explanation:

Step1: Find the GCF of 18 and 81

The greatest common factor (GCF) of 18 and 81 is 9.

Step2: Factor out the GCF

Factor out 9 from \(18 - 81r^{2}\):
\(18 - 81r^{2}=9\times2 - 9\times9r^{2}=9(2 - 9r^{2})\)

Answer:

D. \(9(2 - 9r^{2})\)