Answer: 
Step-by-step explanation:
We know that the general form of the exponential decay formula is
, where y is final amount remaining after t time, A is the original amount and r is the rate of decay
Now, the ratio of strontium-90 remaining, p , as a function of years, t , since the nuclear accident. 
Hence, the ratio of remaining since the nuclear accident is 
The graph graphed is y=1/2x
so
y=1/2x and y=-x+6
y=y so
1/2x=-x+6
times 2 both sides
x=-2x+12
add 2x both sides
3x=12
x=4
sub back
y=1/2x
y=1/2(4)
y=2
(4,2) is the solution
Answer:
Step-by-step explanation:
We assume your equations are intended to be ...

Then the profit equation is ...

The partial derivatives of profit with respect to x and y are zero when profit is maximized.
∂P/∂x = 0 = -2x +2y +2
∂P/∂y = 0 = 2x -18y +94
Simplifying, these equations are ...
Substituting the first into the second gives ...
x -9(x -1) = -47
-8x = -56
x = 7
y = 7 -1 = 6
The company will maximize profit by selling 7000 panels of type A and 6000 panels of type B.
700 x .03 x 20 = 420
420 + 700
1120 is in the account after 20 years
Answer:
a and c
Step-by-step explanation:
because its a 3rd demenshion sphere