Solve (3×7)/(5×8) Raised to Power -3: Negative Exponent Challenge

Question

Insert the corresponding expression:

(3×75×8)3= \left(\frac{3\times7}{5\times8}\right)^{-3}=

Video Solution

Solution Steps

00:00 Simplify the following problem
00:04 According to the laws of exponents, a fraction raised to a negative power (-N)
00:08 is equal to the reciprocal fraction raised to the opposite power(N)
00:12 We will apply this formula to our exercise
00:15 We'll convert to the reciprocal number and raise to the opposite power
00:25 According to the laws of exponents, a fraction that is raised to the power (N)
00:28 is equal to a fraction where both the numerator and denominator are raised to the power (N)
00:31 We will apply this formula to our exercise
00:35 We'll raise both the numerator and denominator to the appropriate power, maintaining the parentheses
00:41 This is the solution

Step-by-Step Solution

To simplify the expression (3×75×8)3 \left(\frac{3\times7}{5\times8}\right)^{-3} , we follow these steps:

  • Step 1: Apply the rule for negative exponents, which states that ab=1ab a^{-b} = \frac{1}{a^b} . For fractions, (ab)n=bnan \left(\frac{a}{b}\right)^{-n} = \frac{b^n}{a^n} .
  • Step 2: Rewrite the expression by applying this rule:
    (3×75×8)3=(5×8)3(3×7)3 \left(\frac{3\times7}{5\times8}\right)^{-3} = \frac{(5\times8)^3}{(3\times7)^3}
  • Step 3: Simplify the expression by recognizing the bases to the power of 3: (5×8)3(3×7)3 \frac{(5\times8)^3}{(3\times7)^3}

The expression can be left as is because it matches one of the choices provided. Performing further calculations here is unnecessary since we have correctly applied the negative exponent rule.

Therefore, the correct simplified form of the expression is (5×8)3(3×7)3 \frac{(5\times8)^3}{(3\times7)^3} , which corresponds to choice 2.

Answer

(5×8)3(3×7)3 \frac{\left(5\times8\right)^3}{\left(3\times7\right)^3}