Witch set of orderd pairs contains only points that are on the graph of the function y=12-3x ,-,,54) ,,,-2) c(-5,,,-12) d(-7,-,0)(2,18)

You can try then by plotting the points in. 
The answer is C

Make sure by plotting in the points, lets take (-5,27)
y = 12 -3(-5)
y = 12 + 15
y = 27
27 = 27
This is correct 

Lets try (-1,15)
y = 12 -3(-1)
y = 12 + 3 
y = 15 
15 = 15
This is correct 

Lets try (8,-12)
y = 12 -3(8)
y = 12 - 24 
y = -12 
-12 = -12
This is correct too. 

The correct ordered pairs are C(-5,27),(-1,15),(8,-12)