Answer:

Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or 
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
Let
m ----> the distance in miles (y-coordinate)
h ----> the time in hours (x-coordinate)
In this problem the constant of proportionality k is given and is equal to
----> the speed
substitute

Let V, be the rate in still water and let C = rate river current
If the boat is going :
upstream, its rate is V-C and if going
downstream, its rate is V+C,
But V = 5C, then
Upstream Rate: 5C - C = 4 C
Downstream rate: 5C+C = 6C
Time = distance/Rate, (or time = distance/speed) , then:
Upstream time 12/4C and
Downstream time: 12/.6C
Upstream time +downstream time:= 2h30 ' then:
12/4C + 12/.6C = 2.5 hours
3/C + 2/C = 5/2 (2.5 h = 5/2)
Reduce to same denominator :
5C = 10 and Rate of the current = 2 mi/h
Answer:
$13.50 is the tip
OR
$81.01 is total bill
Step-by-step explanation:
total of bill multiplied by 20%
$67.51 x .20 = $13.50
For total bill amount:
$67.51 + $13.50 = $81.01
Answer:
109.5% of the bill
Step-by-step explanation:
You have to pay 100% of your bill (or else you wouldn't have paid your bill in full) and as you said, "plus a 9.5% tax". 100+9.5=109.5%
The grapph one. I’m not sure but the others don’t work so I would go with the graph