9

Set 2: Systems Of Equations (Intermediate)

Explanation

Answer: C

PROBLEM

Solve: 4x + 3y = 39, 5x + 4y = 51. Find y.

Solve: 4x + 3y = 39, 5x + 4y = 51. Find y.

A.

10

B.

7

C.

9

✓ Correct
D.

8

Detailed Explanation

Choice C is the best answer. Using elimination or substitution: y = 9

Why others are wrong:
A: 10 is incorrect because it does not satisfy the equation.
B: 7 is incorrect because it does not satisfy the equation.
D: 8 is incorrect because it does not satisfy the equation.