Answer:
25*pi or
78.5 square units.
Step-by-step explanation:
If there was no shaded area, the area of the circle would be pi * r^2
r = 10
Area = pi * 10^2
Area = 100 * pi
Since there is a shaded area, the shaded part looks to be 1/4 of the whole. There's no indication of what it actually is, but 1/4 should be close enough.
Area_shade = 1/4 (100*pi)
Area_shade = 25 * pi
That's one answer.
Another is 25 * 3.14 = 78.5 square units
Answer: y=3/2x
Step-by-step explanation:
First, to find the equation, we can figure out that the cost depends on how many tickets are bought. We can use cost as our y and # of tickets as our x.
An equation in slope intercept form is as follows:
y=mx+b
To get our slope, we must figure out the relationship between the cost and the number of tickets, or the y and the x.
We can use the slope formula,
, to find the slope, m.
= 
Thus, the slope of the equation is 3/2, making our final equation be y=3/2x.
This is a refreshing question!
We are given that
f(r)=ar+b, and
Sum f(r) =125 for r=1 to 5
Sum f(r) = 475 for r=1 to 10.
and we know, using Gauss's method, that
G(n)=sum (1,2,3.....n) = n(n+1)/2 or
G(n)=n(n+1)/2
Sum f(r) =125 for r=1 to 5
=>
sum=a(sum of 1 to 5) + 5b => G(5)a+5b=125 [G(5)=15]
15a+5b=125 ...................................................(1)
Similarly, Sum f(r) = 475 for r=1 to 10 => G(10)a+5b=475 [G(10)=55]
=>
55a+10b=475.................................................(2)
Solve system of equations (1) and (2)
(2)-2(1)
55-2(15)a=475-2(125) => 25a=225 =>
a=9
Substitute a=9 in 1 => 15(9)+5b=125 => 5b=-10
b=-2
Substitute a and b into f(r),
f(r)=9r-2
check: sum f(r), r=1,5 = (9-2)+(18-2)+(27-2)+(36-2)+(45-2)=135-10=125 [good]
We define the sum of f(r) for r=1 to n as
S(n)=sum f(r) for r=1 to n = 9(sum 1,2,3....n)-2n = 9n(n+1)/2-2n = 9G(n)-2n
S(n)=9n(n+1)/2-2n
checks:
S(5)=9(15)-2(5)=135-10=125 [good]
S(10)=9(55)-2(10)=495-20=475 [good]
Hence
(a)
S(n)=sum f(r) for r=1,n
= 9(sum i=1,n)+n(-2)
= 9(n(n+1)/2 -2n
=(9(n^2+n)/2) -2n
(b) sum f(r) for i=8,18
=sum f(r) for i=1,18 - sum f(r) for i=1,7
=S(18)-S(7)
=(9(18^2-18)/2-2(18))-(9(7^2-7)/2-2(7))
=1503-238
=1265
Answer:
converted to what?
Step-by-step explanation:
Answer:
c is the answer for 12. because it is a straight line and shows there profit