Advanced MathMediumCoefficient and exponent of a product of monomials
Advanced Math practice question
The expression (3x)² · (2x)³ is equal to kxⁿ, where k and n are constants. What is the value of k + n?
Answer: 77
(3x)² = 9x² and (2x)³ = 8x³. Their product is 72x⁵, so k = 72, n = 5, and k + n = 77.
Common wrong answers
- If you answered 11
- 11 comes from k = 6 (3 × 2) and n = 5, forgetting to apply the powers to the coefficients.
- If you answered 72
- 72 is k alone.
- If you answered 78
- 78 uses n = 6, multiplying the exponents instead of adding.
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