Difficulty: Easy
Correct Answer: 2
Explanation:
Introduction / Context:
This is a straightforward linear equation involving a bracket. The task is to expand the bracket, combine like terms, and solve for the variable x. Such questions test basic algebra skills, especially the correct application of the distributive property and manipulation of equations.
Given Data / Assumptions:
Concept / Approach:
The main steps are: expand the bracket 6(3 − 2x), then collect all terms involving x on one side of the equation and constants on the other side. This will give a simple equation of the form kx = constant. Solving this equation yields the value of x. Care must be taken with the signs when distributing the 6 across the bracket.
Step-by-Step Solution:
Start with 5x + 6(3 − 2x) = 4.Expand the bracket: 6 * 3 = 18 and 6 * (−2x) = −12x.So the equation becomes 5x + 18 − 12x = 4.Combine like terms for x: 5x − 12x = −7x, giving −7x + 18 = 4.Subtract 18 from both sides: −7x = 4 − 18 = −14.Divide both sides by −7: x = (−14) / (−7) = 2.
Verification / Alternative check:
Substitute x = 2 back into the original equation. Compute the bracket first: 3 − 2x = 3 − 4 = −1. Then 6(3 − 2x) = 6(−1) = −6. Now compute 5x + 6(3 − 2x) = 5 * 2 + (−6) = 10 − 6 = 4, which matches the right-hand side. Therefore x = 2 is indeed the correct solution.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
2
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