# How do you factor # 27x^3 + 54 x^2 + 36x +8# by grouping?

##### 1 Answer

Jun 19, 2016

#### Answer:

Note that the first and last terms are perfect cubes and find:

#27x^3+54x^2+36x+8 = (3x+2)^3#

#### Explanation:

Notice that the ratio between the first and second coefficients is not the same as that between the third and fourth.

That is:

So this does not factor by grouping.

Note that the first and last terms are both perfect cubes:

#27x^3 = (3x)^3#

#8 = 2^3#

So we might try

#(3x+2)^3 = 27x^3+54x^2+36x+8#

Yes - that's our factoring.