Question

Line M is represented by the following equation: x − y = 8 Which equation completes the system that is satisfied by the solution (18, 10)?
a. 2x − y = 26
b. x + y = 18
c. 2x − 2y = 36
d. x − y = −28

Answer 1

just check and see which equation has a solution to point (18, 10).

x - y = 8
18 - 10 = 8 
8 = 8    

a. 2x - y = 26
     2(18) - 10 = 26
     36 - 10 = 26
     26 = 26                a solution.

so the answer is a.

hope this helps, God bless!