Step 1 :
Rewrite $ a^{6}-64 $ as:
$$ a^{6}-64 = (a^{3})^2 - (8)^2 $$Now we can apply the difference of squares formula.
$$ I^2 - II^2 = (I - II)(I + II) $$After putting $ I = a^{3} $ and $ II = 8 $ , we have:
$$ a^{6}-64 = (a^{3})^2 - (8)^2 = ( a^{3}-8 ) ( a^{3}+8 ) $$Step 2 :
To factor $ a^{3}-8 $ we can use difference of cubes formula:
$$ I^3 - II^3 = (I - II)(I^2 + I \cdot II + II^2) $$After putting $ I = a $ and $ II = 2 $ , we have:
$$ a^{3}-8 = ( a-2 ) ( a^{2}+2a+4 ) $$Step 3 :
Step 3: Identify constants $ \color{blue}{ b }$ and $\color{red}{ c }$. ( $ \color{blue}{ b }$ is a number in front of the $ x $ term and $ \color{red}{ c } $ is a constant). In our case:
$$ \color{blue}{ b = 2 } ~ \text{ and } ~ \color{red}{ c = 4 }$$Now we must discover two numbers that sum up to $ \color{blue}{ 2 } $ and multiply to $ \color{red}{ 4 } $.
Step 4: Find out pairs of numbers with a product of $\color{red}{ c = 4 }$.
| PRODUCT = 4 | |
| 1 4 | -1 -4 |
| 2 2 | -2 -2 |
Step 5: Because none of these pairs will give us a sum of $ \color{blue}{ 2 }$, we conclude the polynomial cannot be factored.
Step 4 :
To factor $ a^{3}+8 $ we can use sum of cubes formula:
$$ I^3 - II^3 = (I + II)(I^2 - I \cdot II + II^2) $$After putting $ I = a $ and $ II = 2 $ , we have:
$$ a^{3}+8 = ( a+2 ) ( a^{2}-2a+4 ) $$Step 5 :
Step 5: Identify constants $ \color{blue}{ b }$ and $\color{red}{ c }$. ( $ \color{blue}{ b }$ is a number in front of the $ x $ term and $ \color{red}{ c } $ is a constant). In our case:
$$ \color{blue}{ b = 2 } ~ \text{ and } ~ \color{red}{ c = 4 }$$Now we must discover two numbers that sum up to $ \color{blue}{ 2 } $ and multiply to $ \color{red}{ 4 } $.
Step 6: Find out pairs of numbers with a product of $\color{red}{ c = 4 }$.
| PRODUCT = 4 | |
| 1 4 | -1 -4 |
| 2 2 | -2 -2 |
Step 7: Because none of these pairs will give us a sum of $ \color{blue}{ 2 }$, we conclude the polynomial cannot be factored.
Step 6 :
Step 6: Identify constants $ \color{blue}{ b }$ and $\color{red}{ c }$. ( $ \color{blue}{ b }$ is a number in front of the $ x $ term and $ \color{red}{ c } $ is a constant). In our case:
$$ \color{blue}{ b = -2 } ~ \text{ and } ~ \color{red}{ c = 4 }$$Now we must discover two numbers that sum up to $ \color{blue}{ -2 } $ and multiply to $ \color{red}{ 4 } $.
Step 7: Find out pairs of numbers with a product of $\color{red}{ c = 4 }$.
| PRODUCT = 4 | |
| 1 4 | -1 -4 |
| 2 2 | -2 -2 |
Step 8: Because none of these pairs will give us a sum of $ \color{blue}{ -2 }$, we conclude the polynomial cannot be factored.