Simplify 8^(-10) × 8^(-5) × 8^9: Combining Like Base Exponents

Question

Insert the corresponding expression:

810×85×89= 8^{-10}\times8^{-5}\times8^9=

Video Solution

Solution Steps

00:00 Simplify the following problem
00:04 According to the laws of exponents, the multiplication of powers with the same base (A)
00:07 equals the same base raised to the sum of the exponents (N+M)
00:11 We will apply this formula to our exercise
00:15 We'll maintain the base and add the exponents together
00:19 Given that we are multiplying a negative factor, we must be careful with the parentheses
00:36 A positive x A negative always equals a negative, therefore we subtract as follows
00:40 Let's calculate
00:48 According to the laws of exponents, any number with a negative exponent (-N)
00:51 equals its reciprocal raised to the opposite exponent (N)
00:54 We will apply this formula to our exercise
00:57 We'll convert to the reciprocal number and raise it to the opposite exponent
01:01 This is the solution

Step-by-Step Solution

To solve this problem, we need to simplify the expression 810×85×89 8^{-10} \times 8^{-5} \times 8^9 using exponent rules.

  • Step 1: Apply the multiplication rule for exponents. This rule states that when multiplying expressions with the same base, you add their exponents. Thus, we calculate:
    810×85×89=810+(5)+9 8^{-10} \times 8^{-5} \times 8^9 = 8^{-10 + (-5) + 9} .
  • Step 2: Simplify the exponents:
    10+(5)+9=105+9=6 -10 + (-5) + 9 = -10 - 5 + 9 = -6 .
  • Step 3: The expression simplifies to:
    86 8^{-6} .
  • Step 4: Convert the negative exponent into a positive one by using the rule for negative exponents, where an=1an a^{-n} = \frac{1}{a^n} :
    86=186 8^{-6} = \frac{1}{8^6} .

Therefore, the simplified expression is 186 \frac{1}{8^6} .

The corresponding expression is:

186 \frac{1}{8^6}

Answer

186 \frac{1}{8^6}