A = Pe^rt
Amount of interest paid = Principal*e^ (rate*time)
(The rate must be in decimal form)
3.15% / 100 = .0315
1,512 = P[e^(.0315*12)]
1,512 / e^(.0315*12) = P
1036.06 = P
$1036.06 was the Principal
** I left that value unrounded to the hundreds place because one doesn’t round with money. :)
Good luck!
Answer: Choice A
Step-by-step explanation:
The correct answer is choice A. The equation 81 - a is doing exactly what the question is asking for. It represents 81 minus an unknown number, with the unknown number being shown as a.

<h2>
Explanation:</h2>
In this exercise, we have the following point:

Let's assume that y varies directly as x, so this implies we can writ y as the product of x and some non-zero real constant k. In a mathematical language:

As you can see, this is the equation of a line whose slope is k and passes through the origin. Therefore, the slope of the line is the constant of proportionality we are looking for:

<h2>Learn more:</h2>
Direct and indirect proportionality: brainly.com/question/10945121
#LearnWithBrainly
Answer:
Step-by-step explanation:
for 2.2 you would still have 5^2 in brackets still
same kind of error for 2.1
9514 1404 393
Answer:
(x, y) = (5, 4)
Step-by-step explanation:
Subtracting the second equation from the first eliminates the x term.
(4x +6y) -(4x +2y) = (44) -(28)
4y = 16 . . . . simplify
y = 4
Using the second equation to find x, we have ...
4x +2(4) = 28
x + 2 = 7 . . . . . . divide by 4
x = 5 . . . . . . . . . subtract 2
The solution is (x, y) = (5, 4).