Difficulty: Medium
Correct Answer: 1/6
Explanation:
Introduction / Context:
This question checks your ability to solve a linear equation involving fractions and brackets. Such questions are common in aptitude and school mathematics, and they test algebraic manipulation skills, especially dealing with fractional coefficients and clearing denominators in a neat way. The goal is to isolate x and express it as a simple rational number.
Given Data / Assumptions:
Concept / Approach:
The standard approach is to first remove fractions by multiplying through by a common multiple of the denominators. Here, denominators are 3, 5, and 4. However, you can also simplify step by step. First expand the bracket, then combine like terms, and finally solve for x by isolating the variable. Careful handling of fractions is essential to avoid arithmetic mistakes.
Step-by-Step Solution:
Start with (2/3) * (6x/5 − 1/4) + 1/3 = 9x/5.Multiply both sides by 3 to clear the denominator 3: 2 * (6x/5 − 1/4) + 1 = 27x/5.Expand the left side: 2 * (6x/5) = 12x/5 and 2 * (−1/4) = −1/2, so the left side is 12x/5 − 1/2 + 1.Combine constants: −1/2 + 1 = 1/2, so we have 12x/5 + 1/2 = 27x/5.Subtract 12x/5 from both sides: 1/2 = 27x/5 − 12x/5 = 15x/5 = 3x.So 3x = 1/2, and dividing both sides by 3 gives x = 1/6.
Verification / Alternative check:
Substitute x = 1/6 into the original equation. Compute 6x/5 = 6 * (1/6) / 5 = 1/5 and 1/4 remains 1/4. So 6x/5 − 1/4 = 1/5 − 1/4 = (4 − 5) / 20 = −1/20. Then (2/3) * (−1/20) = −1/30. Add 1/3 to this: −1/30 + 1/3 = −1/30 + 10/30 = 9/30 = 3/10. Now compute the right side: 9x/5 = 9 * (1/6) / 5 = 9/6 * 1/5 = 3/10. Both sides are equal, so x = 1/6 is correct.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
1/6
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