1

Set 4: Linear Equations (Advanced)

Explanation

Answer: B

Solve for xx: x15=3\frac{x}{15} = 3

A.

5

B.

45

✓ Correct
C.

18

D.

0.2

Detailed Explanation

Choice B is correct. Choice B is the correct answer. To eliminate the fraction, we multiply both sides by the denominator. 1. Start with the equation: x15=3\frac{x}{15} = 3 2. Multiply both sides by 15: x=3×15x = 3 \times 15 3. Calculate: x=45x = 45 4. Verify: 4515=3\frac{45}{15} = 3 ✓ Check Your Work: You can verify mentally: "45 divided by 15 is 3" or "15 times 3 is 45." Choice A is incorrect because this results from adding: 15+3=1815+ 3 = 18. Addition is not the inverse of division. Choice B is incorrect because this comes from dividing 15 by 3 instead of multiplying: 153=5\frac{15}{3} = 5. This is backwards. Choice D is incorrect because this results from dividing 3 by 15: 315=0.2\frac{3}{15} = 0.2. This divides in the opposite direction.

Key Steps:

The correct answer is 45

Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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