Answer:
The formula for area of a circle is A = tt r^2
So 3.14 * 3.5^2 = 38.5
Step-by-step explanation:
Let Jean's speed while running = x mph
Then Jean's speed while riding will be = x+9 mph
Distance covered by running = 8 miles
Distance covered by riding = 11 miles
Total time taken to complete the race = 1.5 hours
As, 
So, time for running= 
And time for riding= 
Equation becomes:

Now, multiply every term by 2x(x+9) to clear denominators:

Simplifying it we get

Solve the quadratic equation using formula

putting a=3 , b= -11, c= -144
we get (x - 9)(3x + 16) = 0
where x=9 and x=
Neglect the negative answer as speed cannot be negative, so x = 9 mph
Hence, Jean's running speed is 9 mph and riding speed is x+9 = 9+9 = 18 mph
Answer:

Step-by-step explanation:
Each term of this Geometric Series (3, −6, 12, −24, ...) can also be found through this explicit formula:
Because the
term is found by the product of its common ratio "q", times its predecessor n-1. Where n, refers to the order of the term.
So let's test it, suppose we want to find the 4th term. We know the common ratio and the first term. Then we can write f(n) as:

f(4)=f(3)*-2⇒-24=12*-2⇒-24=-24
The explicit formula is ok.
The formula for the total sum of the inner angles of the polygon is
Sn= (n-2) 180°
1) S6= (6-2) 180 = 4*180 = 720° In the hexagon all angles are equal
α= S6/6= 720/6= 120°
2) In each polygon the sum of the external angles is 360°
3) S5= (5-2) 180 = 540° than we can add up all angles
x+131+108+107+110=540 => x= 540-456= 84°
4) α = 360/5=72°
Good luck!!!