Answer:
a.
b. $37.50
Step-by-step explanation:
To find out how much the 5 were paying in total, we can add the bill and the tip. This gives us x + 10. Since there are 5 people and they are splitting the bill equally, the total amount would be divided by 5 to get the amount each person pays: 
. We already know the amount they each paid, as it is given as $9.50. Both expressions represent the same thing, do we can set them equal to each other:
Now, we can solve.
First, we can multiply by 5 on both sides to get:
47.5 = x + 10
And then subtract 10:
x = 37.5
This means the bill before the tip was $37.50
Plan A costs a total of $95 since it says $95 for unlimited talk and text.
Plan B:
(.10 x 800) + (.05 x 1000)
The (.10 x 800) represents 10 cents per talk minute for 800 minutes.
The (.05 x 1000) represents 5 cents per text message for 1000 text messages.
Solve:
.10 x 800 = 80
.05 x 1000 = 50
80 + 50 = 130
This means Plan B will cost him $130 under these conditions.
Plan C:
20 + ((.05 x 800)+(.05 x 1000))
The 20 + represents a flat rate of $20 per month.
The (.05 x 800) represents 5 cents per call minute.
The (.05 x 1000) represents 5 cents per text.
Solve:
.05 x 800 = 40
.05 x 1000 = 50
20 + 40 + 50 = 110
This means Plan C will cost him $110 under these conditions.
Plan D:
45 + (.10(800 - 500))
The 45 + represents a flat monthly rate of $45.
The (800 - 500) represents how many minutes he has to pay for with the 500 free.
The .10 is the cost per extra minute.
Solve:
800 - 500 = 300
.10 x 300 = 30
45 + 30 = 75
This means Plan D will cost him $75 under these conditions.
In short:
Plan A- $95
Plan B- $130
Plan C- $110
Plan D- $75
The least expensive among these is Plan D, which only costs $75 per month.
Tom because his fish is 1.5 pounds and kiras fish is 1.14 pounds
The volume of the pool is 1,620 ft cubed
