Answer:
Step-by-step explanation:
Answer:
x=-5, y=-1
Step-by-step explanation:
Substitute x=-4+y into -2x-5y=15. So we have
-2(-4+y)-5y=15
8-2y-5y=15
-7y=7
y=-1
And x is -4+y so x= -4+(-1)= -5.
Answer:
P(t) = 27000 * (1/9)^(t/4)
Step-by-step explanation:
This problem can me modelled with an exponencial formula:
P = Po * (1+r)^t
Where P is the final value, Po is the inicial value, r is the rate and t is the amount of time.
In this problem, we have that the inicial population/value is 27000, the rate is -8/9 (negative because the population decays), and the time t is in months, so as the rate is for every 4 months, we use the value (t/4) in the exponencial.
So, our function will be:
P(t) = 27000 * (1-8/9)^(t/4)
P(t) = 27000 * (1/9)^(t/4)
7. the formula for octagon is a=2(1+radical2)s^2
s=4
a=about 77.25
8.
