9514 1404 393
Answer:
(x, y) = (-11, 4)
Step-by-step explanation:
You can subtract 3 times the second equation from the first to eliminate y.
(7x +9y) -3(x +3y) = (-41) -3(1)
4x = -44
x = -11
Substituting into the second equation gives ...
-11 +3y = 1
3y = 12
y = 4
The solution is (x, y) = (-11, 4).
The answer would be A. I just did this yesterday. Do you want the steps?
2n+9+5n=30 combine like terms on left side
7n+9=30 subtract 9 from both sides
7n=21 divide both sides by 7
n=3
The equation will be of the form:

where A is the amount after t hours, and r is the decay constant.
To find the value of r, we plug the given values into the equation, giving:

Rearranging and taking natural logs of both sides, we get:


The required model is:
A negative plus a negative equals a negative so it's just -17