Question

Factor the greatest common factor.
-30k^6 + 9k^5 - 21k^4

Answer 1

The GCF is -3k^4
-30k^6+9k^5-21k^4= -3k^4(10k^2-3k+7)

Answer 2

Since both terms are perfect squares, factor using the difference of squares formula,

a

2

−

b

2

=

(

a

+

b

)

(

a

−

b

)

where

a

=

k

2

and

b

=

1

.

9

(

−

36

k

6

+

k

5

−

k

−

2

)