9

Set 2: Systems Of Equations (Advanced)

Explanation

Answer: A

PROBLEM

Solve: x + 5y = 40, 3x + 4y = 43. Find x.

Solve: x + 5y = 40, 3x + 4y = 43. Find x.

A.

5

✓ Correct
B.

7

C.

6

D.

3

Detailed Explanation

Choice A is the best answer. Using elimination or substitution: x = 5

Why others are wrong:
B: 7 is incorrect because it does not satisfy the equation.
C: 6 is incorrect because it does not satisfy the equation.
D: 3 is incorrect because it does not satisfy the equation.