Answer:
The area of the resulting cross section is 
Step-by-step explanation:
we know that
The resulting cross section is a circle congruent with the circle of the base of cylinder
therefore
The area is equal to

we have

-----> the radius is half the diameter
substitute the values

If a = first term and r = common ratio we have
a + ar + ar^2 = 13 and ar^2 / a = r^2 = 9
so r = 3
and a + 3a + 9a = 13
so a = 1
so they are 1,3 and 9
2.
in geometric series we have
4 , 4r ,4r^2 , 60
Arithmetic;
4, 4r , 4r + d , 4r + 2d
so we have the system of equations
4r + 2d = 60
4r^2 = 4r + d
From first equation
2r + d = 30
so d = 30 - 2r
Substitute for d in second equation:-
4r^2 - 4r - (30-2r) = 0
4r^2 - 2r - 30 =0
2r^2 - r - 15 = 0
(r - 3)(2r + 5) = 0
r = 3 or -2.5
r must be positive so its = 3
and d = 30 - 2(3) = 24
and the numbers are 4*3 = 12 , 4*3^2 = 36
first 3 are 4 , 12 and 36 ( in geometric)
and last 3 are 12, 36 and 60 ( in arithmetic)
The 2 numbers we ause are 12 and 36.
Answer:
Therefore 80 ceperies will he need to sell this month.
Step-by-step explanation:
Average: Average is the ratio of sum of all numbers to the total number present in the data.
Given that Herbert has sold 99, 37, 86 and 73 copeirs in the last 4 months.
Let he need to sell x copeirs in this month.
According to the problem,

⇒ 99+37+86+73+x= 75×5
⇒295 + x= 375
⇒x = 375 - 295
⇒ x= 80
Therefore 80 ceperies will he need to sell this month.
<h3>
Answer:</h3>
infinite solutions
<h3>
Step-by-step explanation:</h3>
Add the two equations.
... (-4x) + (y) = (y +3) +(-4x -3)
Add 4x -y to both sides.
... -4x +y +4x -y = -4x +y +4x -y
... 0 = 0 . . . . . true for all values of x (or y)
Both equations describe the same line.
_____
The graph shows the first equation as a red line. The second equation is shown using a "blue dot" texture, so you can see it overlays the red line.