Answer:
10=10
Step-by-step explanation:
y-3x+15=10
y=3x-15+10
y=3x-5
subtitute y=3x-5 in the above equation:
3x-5-3x+15=10 (3x will be eliminated with -3x)
-5+15=10
10=10
(i hope this is the way you want the answer but at least I think it is correct)
