Solve: a²÷a + a³×a⁵ Expression Using Laws of Exponents

Question

Solve the exercise:

a2:a+a3a5= a^2:a+a^3\cdot a^5=

Video Solution

Solution Steps

00:00 Simplify the expression
00:05 Represent the division as a fraction
00:13 According to the laws of exponents when dividing with the same base(A)
00:18 With different exponents(M,N) where M is in the numerator
00:21 We get the same base(A) with exponent(M-N)
00:24 Let's apply it to the question
00:27 We keep the base(A) and subtract the exponents(2-1)
00:38 According to the laws of exponents, multiplication with the same base(A) with exponents N,M
00:42 Will be equal to the same base(A) with exponent (N+M)
00:46 Let's apply it to the question
00:49 We keep the base(A) and sum the exponents(3+5)
00:52 Let's calculate all the exponents
01:00 Let's factor out the common base A
01:06 This is the simplified expression and the solution to the question

Step-by-Step Solution

First we rewrite the first expression on the left of the problem as a fraction:

a2a+a3a5 \frac{a^2}{a}+a^3\cdot a^5 Then we use two properties of exponentiation, to multiply and divide terms with identical bases:

1.

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

2.

bmbn=bmn \frac{b^m}{b^n}=b^{m-n}

Returning to the problem and applying the two properties of exponentiation mentioned earlier:

a2a+a3a5=a21+a3+5=a1+a8=a+a8 \frac{a^2}{a}+a^3\cdot a^5=a^{2-1}+a^{3+5}=a^1+a^8=a+a^8

Later on, keep in mind that we need to factor the expression we obtained in the last step by extracting the common factor,

Therefore, we extract from outside the parentheses the greatest common divisor to the two terms which are:

a a We obtain the expression:

a+a8=a(1+a7) a+a^8=a(1+a^7) when we use the property of exponentiation mentioned earlier in A.

a8=a1+7=a1a7=aa7 a^8=a^{1+7}=a^1\cdot a^7=a\cdot a^7

Summarizing the solution to the problem and all the steps, we obtained the following:

a2a+a3a5=a(1+a7) \frac{a^2}{a}+a^3\cdot a^5=a(1+a^{7)}

Therefore, the correct answer is option b.

Answer

a(1+a7) a(1+a^7)