N + d = 21
0.5n + 0.10d = 1.35
5n + 10d = 135
d = 21-n
5n + 210 - 10n = 135
-5n = -75
n = 15
d = 6
There are 16 cups in a gallon.
<span>At the top of a ramp, all of the energy of the car is potential: that is, it has yet to be moved but has the ability to move. As the car is sliding down the ramp, the potential energy is being transformed into kinetic energy, which reaches a maximum at halfway down the ramp. After this point, the kinetic energy begins to lessen and the potential energy begins to increase, until the car comes to a full stop, at which point kinetic energy is at zero and the potential energy is again at a maximum.</span>
4b+21=-3b+21+7b
4b+21=4b+21
it means that the expression shows an identity
Using simple interest, it is found that $13,872 was loaned at 9%.
<h3>Simple Interest</h3>
The amount of money after t years in simple interest is modeled by:

In which:
- r is the interest rate, as a decimal.
The interest earned is:

A bank loaned out $14000, in two parts, hence:

Part of it at the rate of 9% per year and the rest at 17% per year, hence:

The interest received in one year totaled $2000, hence:

Then:



Isolating
as a function of
, then we can replace on the equation for the first interest.



Then:






$13,872 was loaned at 9%.
To learn more about simple interest, you can take a look at brainly.com/question/25296782