Step-by-step explanation:

5 is a constant - you pay $5 before you go on any of the waterslides.
let the number of waterslides Steven went on = x
5 +2x =17 ($5 plus $2 per waterslide ride = 17)
Answer a is correct.
By the way, Steven went on 6 waterslide rides.
Unit Rate:
6 plants in 1 square yard
Square yard for every 100 grass seeds
8 seeds per square foot
2 plants per square foot
Rate:
25 trees per 25 yards
4 acres for 800 plants
Answer
the second one, and 5th one
Step-by-step explanation:
because it is liquid