AlgebraMediumSolving a system by substitution
Algebra practice question
Which ordered pair (x, y) is the solution to the system y = x − 2 and 2x + y = 16?
- A. (6, 4)Correct
- B. (4, 6)
- C. (7, 2)
- D. (5, 3)
Answer: A. (6, 4)
Substitute: 2x + (x − 2) = 16, so 3x = 18, x = 6, y = 4.
Why the other answers are wrong
- B. (4, 6)
- (4, 6): y = x − 2 fails (6 ≠ 2).
- C. (7, 2)
- (7, 2): 2 ≠ 5.
- D. (5, 3)
- (5, 3): 10 + 3 = 13 ≠ 16.
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