Simplify 12⁴ × 12⁻⁶: Combining Positive and Negative Exponents

Question

124126=? 12^4\cdot12^{-6}=\text{?}

Video Solution

Solution Steps

00:06 Let's solve this math problem together.
00:09 Using exponent rules, when a number A is raised to M,
00:13 and multiplied by the same number A raised to N,
00:17 it's like A raised to M plus N.
00:20 Let's use this in our example.
00:23 We have 12 raised to the power of 4 plus negative 6.
00:28 Now, let's simplify this exponent.
00:31 Remember, A to the power of negative N,
00:35 equals 1 divided by A to the power of N.
00:39 We'll use this rule now.
00:41 It's 1 divided by 12 raised to the power of 2.
00:45 Let's find 12 squared.
00:48 And that's our solution!

Step-by-Step Solution

We begin by using the power rule of exponents; for the multiplication of terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n} We apply it to the given problem:

124126=124+(6)=1246=122 12^4\cdot12^{-6}=12^{4+(-6)}=12^{4-6}=12^{-2} When in a first stage we apply the aforementioned rule and then simplify the subsequent expression in the exponent,

Next, we use the negative exponent rule:

an=1an a^{-n}=\frac{1}{a^n} We apply it to the expression that we obtained in the previous step:

122=1122=1144 12^{-2}=\frac{1}{12^2}=\frac{1}{144} Lastly we summarise the solution to the problem: 124126=122=1144 12^4\cdot12^{-6}=12^{-2} =\frac{1}{144} Therefore, the correct answer is option A.

Answer

1144 \frac{1}{144}