Solve for x and y from power equations, then compare: I. x^3 × 13 = x^2 × 247 II. y^(1/3) × 14 = 294 ÷ y^(2/3) Find the correct relationship between x and y (x > y, x < y, x = y, or cannot be determined).

Difficulty: Medium

Correct Answer: x < y

Explanation:


Introduction / Context:
Two separate equations define numeric values for x and y via powers. After solving both exactly, we compare their sizes and select a single relationship statement.

Given Data / Assumptions:

  • I: x^3 × 13 = x^2 × 247, x ≠ 0 allows cancellation of x^2.
  • II: y^(1/3) × 14 = 294 ÷ y^(2/3), y > 0 for real principal fractional powers.


Concept / Approach:
In I, divide by x^2 to isolate x. In II, multiply both sides by y^(2/3) to consolidate powers and solve for y. Then compare numeric values of x and y.

Step-by-Step Solution:

I: 13x^3 = 247x^2 ⇒ for x ≠ 0, 13x = 247 ⇒ x = 247/13 = 19.II: 14y^(1/3) = 294 / y^(2/3). Multiply both sides by y^(2/3): 14y = 294 ⇒ y = 294/14 = 21.Hence x = 19 and y = 21, so x < y.


Verification / Alternative check:
Back-substitute: I: 13*19^3 vs 247*19^2 ⇒ both equal 13*19^3. II: Left = 14*21^(1/3); Right = 294/21^(2/3). Since 21^(1/3) * 21^(2/3) = 21, both sides reduce to 14*21^(1/3) and 14*21^(1/3) respectively.


Why Other Options Are Wrong:

  • x > y or x = y: Contradicted numerically.
  • Relationship cannot be determined: Both values are found uniquely; comparison is definite.


Common Pitfalls:
Forgetting domain assumptions with fractional exponents or failing to cancel x^2 when x ≠ 0.


Final Answer:

x < y

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