It's the first one. y can equal x as long as y doesn't equal x multiple times. We also know the last two are wrong because they're saying the same thing. A linear function is a straight line.
Answer:
Step-by-step explanation:
(6 gal)/(4/7 fence) = (21/2 gal)/fence = (10.5 gal)/fence
5z
3z+5z-3z(3z gets cancelled)