Question

Which answer is a solution of the equation?

2x + y = 5

A. 5
B. (1, 2)
C. (2, -1)
D. (3, -1)

Thank you everyone!

Answer 1

2x + y = 5

Put the coordinates of the points to the equation and check it:

A. 5 - not make sense

B. (1, 2) - x = 1, y = 2

2(1) + 2 = 2 + 2 = 4 ≠ 5 NOT

C. (2, -1) - x = 2, y = -1

2(2) + (-1) = 4 - 1 = 2 ≠ 5 NOT

D. (3, -1) - x = 3, y = -1

2(3) + (-1) = 6 - 1 = 5 YES

Answer: D. (3, -1).