Examples with solutions for Power of a Quotient Rule for Exponents: Solving the problem

Exercise #1

406736490=? \frac{4^0\cdot6^7}{36^4\cdot9^0}=\text{?}

Video Solution

Step-by-Step Solution

First we'll use the fact that raising any number to the power of 0 gives the result 1, mathematically:

X0=1 X^0=1

We'll apply this to both the numerator and denominator of the fraction in the problem:

406736490=1673641=67364 \frac{4^0\cdot6^7}{36^4\cdot9^0}=\frac{1\cdot6^7}{36^4\cdot1}=\frac{6^7}{36^4}

Next we'll note that -36 is a power of the number 6:

36=62 36=6^2

And we'll use this fact in the denominator to get expressions with identical bases in both the numerator and denominator:

67364=67(62)4 \frac{6^7}{36^4}=\frac{6^7}{(6^2)^4}

Now we'll recall the power rule for power of a power to simplify the expression in the denominator:

(am)n=amn (a^m)^n=a^{m\cdot n}

And we'll also recall the power rule for division between terms with identical bases:

aman=amn \frac{a^m}{a^n}=a^{m-n}

We'll apply these two rules to the expression we got above:

67(62)4=67624=6768=678=61 \frac{6^7}{(6^2)^4}=\frac{6^7}{6^{2\cdot4}}=\frac{6^7}{6^8}=6^{7-8}=6^{-1}

Where in the first stage we applied the first rule we mentioned earlier - the power of a power rule and simplified the expression in the exponent of the denominator term, then in the next stage we applied the second power rule mentioned before - the division rule for terms with identical bases, and again simplified the expression in the resulting exponent,

Finally we'll use the power rule for negative exponents:

an=1an a^{-n}=\frac{1}{a^n}

And we'll apply it to the expression we got:

61=16 6^{-1}=\frac{1}{6}

Let's summarize everything we did, we got that:

406736490=16 \frac{4^0\cdot6^7}{36^4\cdot9^0}=\frac{1}{6}

Therefore the correct answer is A.

Answer

16 \frac{1}{6}

Exercise #2

Solve the following:

35xy77xy8x5y= \frac{35x\cdot y^7}{7xy}\cdot\frac{8x}{5y}=

Video Solution

Answer

8xy5 8xy^5

Exercise #3

Solve:

8x7y32042x5y2= \frac{8x^7y^3}{20}\cdot\frac{4}{2x^5y^2}=

Video Solution

Answer

4x2y5 \frac{4x^2y}{5}