Factor polynomial $$ 27a^{3}+64 $$

$$ 27a^{3}+64 = ( 3a+4 )( 9a^{2}-12a+16 ) $$

Step 1 :

To factor $ 27a^{3}+64 $ we can use sum of cubes formula:

$$ I^3 - II^3 = (I + II)(I^2 - I \cdot II + II^2) $$

After putting $ I = 3a $ and $ II = 4 $ , we have:

$$ 27a^{3}+64 = ( 3a+4 ) ( 9a^{2}-12a+16 ) $$

Step 2 :

Step 2: Identify constants $ a $ , $ b $ and $ c $.
$ a $ is a number in front of the $ x^2 $ term $ b $ is a number in front of the $ x $ term and $ c $ is a constant. In this case:

$$ a = 9 , b = -12 ~ \text{ and } ~ c = 16 $$

Step 3: Multiply the leading coefficient $\color{blue}{ a = 9 }$ by the constant term $\color{blue}{c = 16} $.

$$ a \cdot c = 144 $$

Step 4: Find out two numbers that multiply to $ a \cdot c = 144 $ and add to $ b = -12 $.

Step 5: All pairs of numbers with a product of $ 144 $ are:

PRODUCT = 144
1     144	-1     -144
2     72	-2     -72
3     48	-3     -48
4     36	-4     -36
6     24	-6     -24
8     18	-8     -18
9     16	-9     -16
12     12	-12     -12

Step 6: Find out which factor pair sums up to $\color{blue}{ b = -12 }$

Step 7: Because none of these pairs will give us a sum of $ \color{blue}{ -12 }$, we conclude the polynomial cannot be factored.

Polynomial Factoring Calculator