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Set 6: Linear Equations (Intermediate)

Explanation

Answer: D

If x+47=100x + 47 = 100, what is the value of xx?

A.

47

B.

2.13

C.

147

D.

53

✓ Correct

Detailed Explanation

Choice D is correct. Choice C is the correct answer. This is a practical problem involving nice round numbers. 1. Start with the equation: x+47=100x + 47 = 100 2. Subtract 47 from both sides: x=10047x = 100 - 47 3. Calculate: x=53x = 53 4. Verify: 53+47=10053+ 47 = 100 ✓ Mental Math: You can think of this as "what number plus 47 equals 100?" Counting up from 47 to 100 gives you 53. Choice A is incorrect because this results from adding instead of subtracting: 100+47=147100+ 47 = 147. This is the wrong inverse operation. Choice C is incorrect because this confuses the constant (47) with the solution. Just because 47 appears in the equation doesn't make it the answer. Choice D is incorrect because this results from dividing: 100472.13\frac{100}{47} \approx 2.13. Division is not relevant for this addition equation.

Key Steps:

The correct answer is 53

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

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