Answer:

Step-by-step explanation:
In order to write the series using the summation notation, first we need to find the nth term of the sequence formed. The sequence generated by the series is an arithmetic sequence as shown;
4, 8, 12, 16, 20...80
The nth term of an arithmetic sequence is expressed as Tn = a +(n-1)d
a is the first term = 4
d is the common difference = 21-8 = 8-4 = 4
n is the number of terms
On substituting, Tn = 4+(n-1)4
Tn = 4+4n-4
Tn = 4n
The nth term of the series is 4n.
Since the last term is 80, L = 4n
80 = 4n
n = 80/4
n = 20
This shows that the total number of terms in the sequence is 20
According to the series given 4 + 8 + 12 + 16 + 20+ . . . + 80
, we are to take the sum of the first 20terms of the sequence. Using summation notation;
4 + 8 + 12 + 16 + 20+ . . . + 80 = 
4/3 as a fraction is 1 1/3. The volume of a circle is not a thing, so I am going to assume your asking volume of the balloon.
9 = radius
The volume is of the balloon is 4/3 x 9 x 9 x 9 x 3.14 (pi)
Volume = 3052.08 cubic inches
If you are asking for area of circle
Area of Circle = 9 x 9 x 3.14
Area = 254.34 sq. inches
Answer:
a) y=11x+24
b) The slope of this equation is 11. You get the slope by taking the difference of the number of participants over the difference of the years: 35-57/1-3
c) The y intercept is 24 and it would be before the first year. (?)
d) There should be 79 participants in the fifth year.
Step-by-step explanation:
I hope this helped. I'm not 100 percent sure the explanation for letter c.
Answer:
AAS method can be used to prove that the two triangles are congruent.
Step-by-step explanation:
According to the question for the two triangles one pair of opposite angles are equal. One another pair of angles are equal for the two and one pair of sides are also equal of the two.
Hence, the two given triangles are congruent by AAS rule.
Hence, AAS method can be used to prove that the two triangles are congruent.