Let x=small circle
2x = bigger circle
πx^2 + π(2x)^2 = 80π
x^2 + 4x^2 = 80
5x^2 = 80
x^2 = 16
x = +/- 4
but we need the positive one because there's no negative measurement so
the answers are:
4m and 8m
Answer:
$1,281.00
Step-by-step explanation:
We start by calculating the value $50 added each month after the first month
= $50 × 11
= $550
Calculation:
First, converting R percent to r a decimal
r = R/100 = 5.5%/100 = 0.055 per year.
P = Principal = 500 + 550
= $1050
Calculation:
First, converting R percent to r a decimal
r = R/100 = 5.5%/100 = 0.055 per year.
Solving our equation:
A = 1050(1 + (0.055 × 4)) = 1281
A = $1,281.00
Therefore, there would be $1,281.00 after 4 years.
Let 
be the line that passes through both points.
We know that 
and 
. So:
Solving the system, we get that a= -1 and b = 6.
So the line is equal to 
.
Answer: 35 additional teachers are needed
-------------------------------------------------
-------------------------------------------------
Explanation:
We have 2470 students and the ratio of students to teachers is 26:1. This means that for every teacher, there are 26 students. Put another way, we can set up this ratio
2470/x = 26/1
where x is the number of teachers. Cross multiply and solve for x
2470/x = 26/1
2470*1 = 26*x
2470 = 26x
26x = 2470
26x/26 = 2470/26
x = 95
So we have 95 teachers currently
-------------
Let y be the new number of teachers needed to bring the ratio down to 19:1
Using a similar idea as done above, we would have this ratio
2470/y = 19/1
Let's solve for y
2470/y = 19/1
2470*1 = 19*y
2470 = 19y
19y = 2470
19y/19 = 2470/19
y = 130
So we'll need 130 teachers to have the ratio be 19:1
The difference of the values is y - x = 130 - 95 = 35, which is the final answer. This is the additional amount of teachers needed.
