Answer:
9
Step-by-step explanation:
We can use the distance formula
d = sqrt ( ( y2-y1)^2 + ( x2-x1) ^2)
d = sqrt ( ( 4- -3)^2 + ( -4 -2) ^2)
= sqrt ( ( 7^2 + ( -6)^2)
= sqrt( 49+ 36)
= sqrt(85)
9.219544457
Rounding to the nearest whole number
= 9
First, you need to write to expressions to model each situation:
Plan A: 10+0.15x
Plan B: 30+0.1x
Next, set the expressions equal to each other and solve for x:
10+0.15x=30+0.1x
<em>*Subtract 0.1x from both sides to isolate the variable*</em>
10+0.05x=30
<em>*Subtract 10 from both sides*</em>
0.05x=20
<em>*Divide both sides by 0.05*</em>
x=400
The plans would have the same cost after 400 minutes of calls.
To find how much money the plans cost at 400 minutes, plug 400 into either expression. We'll use Plan A:
10+0.15(400)
10+60
70
The plans will cost $70.
Hope this helps!
Remark
You cannot give an answer to this unless you are give the fastest speed of a swimmer. That stat is not an easy one to decide upon. At what distance for example or do you eliminate distance? Since this is a college level question, I don't think it unreasonable that you have to research raw distance over fastest time.
The fastest speed I can find is 100 meters in 46.91 seconds. That means that the actual speed of the swimmer is 100 meters / 46.91 = 2.132 meters / second.
Givens
Set up a proportion with the numbers found and given
Speed of ball / speed of swimmer = 21.12 / 1
Speed of ball = x
Solution
Speed of swimmer = 2.132 m/s
x / 2.132 = 21.12 / 1 Multiply Both sides by 2.132
x = 21.12 * 2.132 / 1
x = 45.02 m/s
Answer
45.02 m/s
