1

Set 4: Linear Equations

Explanation

Answer: C

If x+12=17x + 12 = 17, what is the value of xx?

A.

29

B.

12

C.

5

✓ Correct
D.

-5

Detailed Explanation

Choice C is correct. Choice C is the correct answer. To solve this one-step linear equation, we need to isolate the variable xx using inverse operations. 1. Start with the equation: x+12=17x + 12 = 17 2. Identify the operation: The variable is currently being added to 12 3. Apply the inverse operation: Subtract 12 from both sides to isolate xx 4. Simplify: x=1712=5x = 17 - 12 = 5 5. Verify the solution: Substitute x=5x = 5 back into the original equation: 5+12=175+ 12 = 17 ✓ Strategic Tip: For equations in the form x+a=bx + a = b, always subtract aa from both sides. Addition and subtraction are inverse operations. Choice D is incorrect because this results from adding 12 to 17 instead of subtracting. The error is: 17+12=2917+ 12 = 29. Remember, we need to undo the addition. Choice D is incorrect because this uses the wrong sign. If you calculate 171217- 12 but mistakenly write the answer as negative, you get 5-5. Always check the sign of your answer. Choice C is incorrect because this confuses the constant term (12) with the solution. The value 12 is what's being added to xx, not the value of xx itself.

Key Steps:

The correct answer is 5

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.
D: Choice D is incorrect and may result from a calculation error.

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