Question

Difficulty: EasyOperations with Variable Exponents

Which of the following represents the simplified form of the expression 4b5⋅2b−24b^5 \cdot 2b^{-2}?

  1. A
    8b−108b^{-10}
  2. B
    6b36b^3
  3. 8b38b^3Answer
  4. D
    8b78b^7

Answer

The simplified expression is 8b38b^3.
The correct expression is found by multiplying the numerical coefficients (4×2=84 \times 2 = 8) and adding the exponents for the common base bb (5+(−2)=35 + (-2) = 3), resulting in 8b38b^3.

Step-by-Step Solution

1
Multiply the numerical coefficients.
4×2=84 \times 2 = 8
When multiplying algebraic terms, their numerical coefficients are multiplied together.
2
Apply the product rule of exponents to the variable terms.
b5⋅b−2=b5+(−2)=b3b^5 \cdot b^{-2} = b^{5 + (-2)} = b^3
When multiplying exponential expressions with the same base, add their exponents.
3
Combine the coefficient and the variable term.
8b38b^3
This is the final simplified form of the expression.

Key Concept

When multiplying two exponential terms with the same base, multiply their coefficients and add their exponents.
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