EXPLANATION
Given the ordered pairs:
 x y
 
 0 _1_
 __ 0
 __ 5
Plugging in x=0 into x + 5y = 15:
 0 + 5y = 5
Dividing both sides by 5:
 y = 1
Then, plugging in y=0 into x + 5y = 15:
 x + 5*0 = 5
Multiplying numbers:
 x = 5
Plugging in y=5 into x + 5y = 15:
 x + 5*5 = 15
Multiplying numbers:
 x + 25 = 15
Subtracting -25 to both sides:
 x = 15 - 25
Subtracting numbers:
 x = -10
Hence, the table is as follows:
 x y
 
 0 _1_
 5 0
 -10 5