Answer:
16. y=-5x-20; 17. y=6x+18, or factored y=6(x+3)
Step-by-step explanation:
Your slope is -5
y=-5x+b, solve for b by pluging the point (-3,-5) in for x and y
-5=-5(-3)+b, solve for b
-20=b, now rewrite the equation
y=-5x-20
Your slope is 6
y=-5x+b, solve for b by pluging the point (-3,-0) in for x and y
0=6(-3)+b, solve for b
18=b, now rewrite the equation
y=6x+18, or factored y=6(x+3)
2/5 = 8/20
3/4= 15/20
Therefore, 3/4 is larger than 2/5~
What do you need to find ? x and y ?
The fromula of a slope:

a) (-1, -8), (-7, -4)
substitute

b) (2.1, 3.8), (3.1, 7.6)
substitute

Answer:
you spend 5 hrs. first you have to substract 45 from 120 because it is a default charge. 120-45 = 75. if you divide 75 by 15 you get 5 hrs. because it 15$ per hour.