Factor the Polynomial Expression: 2a^5 + 8a^6 + 4a^3

Question

Factor the following expression:

2a5+8a6+4a3 2a^5+8a^6+4a^3

Video Solution

Solution Steps

00:00 Simplify the expression by extracting the common factor
00:07 When multiplying powers with equal bases
00:12 The power of the result equals the sum of the powers
00:22 Break down each power into a third power plus the remainder
00:42 We will use this formula in our exercise to extract the common factor
01:03 Break down 8 into factors 2 and 4
01:10 Break down 4 into factors 2 and 2
01:18 Mark common factors with the same color
01:27 Take out the common factor from the parentheses
01:30 Write the remaining factors in order
01:36 And this is the solution to the question

Step-by-Step Solution

We will factorize by extracting the largest common factor. In the given expression, there are the following terms:

2a5,8a6,4a3 2a^5,\hspace{4pt}8a^6,\hspace{4pt}4a^3

We'll start with the letters, using the law of exponents for multiplication between terms with identical bases, but in reverse order:

bm+n=bmbn b^{m+n} =b^m\cdot b^n

to understand that:

a6=a3a3a5=a3a2 a^6=a^3\cdot a^3\\ a^5=a^3\cdot a^2

and we'll note that the highest power of a a that can be extracted as a common factor for all three terms is the power of 3, meaning: a3 a^3 ,

we'll continue and extract the largest common factor for the numbers 2,4,8, which is clearly the number 2 since it is a prime number, therefore we'll conclude and extract the common factor: 2a3 2a^3

We'll apply this to the given expression and extract a common factor:

2a5+8a6+4a3=2a3(a2+4a4+2) 2a^5+8a^6+4a^3 =2a^3(a^2+4a^4+2)

where after extracting the common factor outside the parentheses, we'll look at each term before extracting the common factor separately, asking the question: "By how much did we multiply the common factor to get the current term?" and we'll fill in the missing parts inside the parentheses while making sure that the sign of the term we completed inside the parentheses when multiplied by the sign of the term we extracted outside the parentheses gives us the sign of the original term, it is recommended to verify that the factorization is correct by opening the parentheses, performing the multiplications and confirming that we indeed get the expression before factorization.

Therefore the correct answer is answer A.

Answer

a3(25a2+8a3+4) a^3(25a^2+8a^3+4)