Answer:
11 is 405, 12 is 107.5, 13 im not sure of
Step-by-step explanation:
First on 11 you can just do 21*21 (the big square) and subtract that by 36 (which is 6*6, the small square), you'll get 107.5.
Then on 12, it is made up of a large rectangle, a small triangle, and a flatter triangle. The top triangle's formula is 1/2(7*3) which = 10.5. The big rectangle is 13*7 = 91. The last triangle is 1/2(4*3) which = 6. It is 3 because 13-10. Add all those up and you should get 107.5.
And I just want to know on number 13 if that 11 is the radius or diameter. I can't seem to tell.
Answer:
Step-by-step explanation:

We can write this as:-
P(x) = + x^3 - 5x^2 - 25x + 125
There are 2 changes of real sign so by Descartes Rule of signs there are either 2 positive real roots or 0 positive roots.
P(-x) = - x^3 - 5x^2 + 25x + 125
There is just one change of sign so there is exactly 1 real negative root.
125 is a multiple of 5 so By rational root theorem 5 could be a positive root.
P(5) = 125 - 125 - 125 + 125 = 0 so one zero is 5
if we divide the polynomial by (x - 5) we get the quadratic
x^2 - 25
(x + 5)(x - 5) = 0
x = 5,-5
so the roots are 5 (multiplicity 2) and -5.
2 real positive zeroes and one real negative zero
This is exponential growth/decay type problem...
F=Ir^t, F=final value, I=initial value, r=rate, t=time, in this case I=1250 and r=(1-.045)=0.955 so
F=1250(.955)^t and we want to find t for when F=800
800=1250(.955)^t
.64=.955^t take the natural log of both sides...
ln.64=t ln.955
t=(ln.64)/ln.995
t≈9.69 weeks
t≈9.69 weeks (to nearest hundredth of a week)