Simplify the Exponential Expression: (a^2x/a^y) × (a^2y/a^-y)

Exponential Laws with Fraction Multiplication

Solve the following exercise:

a2xay×a2yay= \frac{a^{2x}}{a^y}\times\frac{a^{2y}}{a^{-y}}=

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Simplify the following expression
00:03 When dividing powers with equal bases
00:06 The power of the result equals the difference of the exponents
00:13 We'll use this formula in our exercise, and subtract the exponents
00:35 When multiplying powers with equal bases
00:40 The power of the result equals the sum of the exponents
00:43 We'll apply this formula to our exercise, and then add together the exponents
00:57 Let's factor out 2
01:00 This is the solution

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Solve the following exercise:

a2xay×a2yay= \frac{a^{2x}}{a^y}\times\frac{a^{2y}}{a^{-y}}=

2

Step-by-step solution

The following problem involves a multiplication operation between two fractions.

Let's begin by applying the rule for multiplying fractions. It states that multiplication of two fractions is calculated by placing one fraction over a line and then proceeding to multiply the numerators together and multiplying the denominators together.

xywm=xwym \frac{x}{y}\cdot\frac{w}{m}=\frac{x\cdot w}{y\cdot m}

Let's apply it to the problem:

a2xaya2yay=a2xa2yayay \frac{a^{2x}}{a^{y}}\cdot\frac{a^{2y}}{a^{-y}}=\frac{a^{2x}\cdot a^{2y}}{a^y\cdot a^{-y}}

Note that in both the numerator and denominator separately there exists a multiplication operation between terms with identical bases. Hence we'll apply the power law for multiplying terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n} Let's apply it separately to the numerator and denominator in the problem:

a2xa2yayay=a2x+2yay+(y)=a2x+2ya0 \frac{a^{2x}\cdot a^{2y}}{a^y\cdot a^{-y}}=\frac{a^{2x+2y}}{a^{y+(-y)}}=\frac{a^{2x+2y}}{a^0}

Next, remember that any number to the power of 0 mathematically equals 1 :

a0=1 a^0=1

So let's return to the problem:

a2x+2ya0=a2x+2y1=a2x+2y \frac{a^{2x+2y}}{a^{0}}=\frac{a^{2x+2y}}{1}=a^{2x+2y}

Remember that division by 1 doesn't change the value of the number, as shown below:

X:1=X1=X X:1=\frac{X}{1}=X

Let's proceed to examine the result that we obtained above:

a2x+2y  a^{2x+2y}\text{ }

In terms of simplification using the laws of exponents we have indeed finished given that this is the most simplified form of the expression.

However it's worth noting that in the exponent we obtained an expression that can be factored using common factor extraction:

2x+2y=2(x+y) 2x+2y=2(x+y)

In this case the common factor is the number 2,

Let's return to the result of the expression simplification, as follows:

a2x+2y=a2(x+y) a^{2x+2y}=a^{2(x+y)} Therefore the correct answer is C.

3

Final Answer

a2(x+y) a^{2(x+y)}

Key Points to Remember

Essential concepts to master this topic
  • Multiplication Rule: When multiplying fractions, multiply numerators together and denominators together
  • Power Law: For same bases: aman=am+n a^m \cdot a^n = a^{m+n}
  • Verification: Check that a0=1 a^0 = 1 and factor common terms ✓

Common Mistakes

Avoid these frequent errors
  • Adding exponents incorrectly when dividing
    Don't forget that aman=amn \frac{a^m}{a^n} = a^{m-n} , not am+n a^{m+n} ! Adding instead of subtracting gives wrong results like a4x+2y a^{4x+2y} instead of a2x+3y a^{2x+3y} . Always remember: division means subtract exponents, multiplication means add exponents.

Practice Quiz

Test your knowledge with interactive questions

\( 112^0=\text{?} \)

FAQ

Everything you need to know about this question

Why do we multiply the fractions instead of adding them?

+

The × symbol means multiplication! When multiplying fractions, we use ab×cd=acbd \frac{a}{b} \times \frac{c}{d} = \frac{a \cdot c}{b \cdot d} . This is different from adding fractions where we need common denominators.

How do I know when to add or subtract exponents?

+

Multiplication = add exponents: aman=am+n a^m \cdot a^n = a^{m+n}
Division = subtract exponents: aman=amn \frac{a^m}{a^n} = a^{m-n}
Remember: multiply means add, divide means subtract!

What does a0 a^0 equal and why?

+

a0=1 a^0 = 1 for any non-zero number a. This happens because anan=ann=a0 \frac{a^n}{a^n} = a^{n-n} = a^0 , and any number divided by itself equals 1!

Can I factor the final exponent like 2x+2y 2x + 2y ?

+

Yes! 2x+2y=2(x+y) 2x + 2y = 2(x + y) , so a2x+2y=a2(x+y) a^{2x+2y} = a^{2(x+y)} . Factoring often makes the answer look cleaner and matches multiple choice options better.

How do I check my work with exponential expressions?

+

Try substituting simple values like a = 2, x = 1, y = 1 into both the original expression and your answer. If they give the same result, you're likely correct!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Exponents Rules questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations