8

Set 5: Linear Equations (Advanced)

Explanation

Answer: B

If 3(ax + b) = 12x + 15 for all values of x, what is the value of a + b?

What is a + b?

A.

8

B.

9

✓ Correct
C.

7

D.

10

Detailed Explanation

Choice B is correct. Distribute: 3 ax + 3 b = 12 x + 15. Matching coefficients: 3 a = 12, so a = 4; and 3 b = 15, so b = 5. Therefore a + b = 9.

Key Steps:

The correct answer is 9

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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