Answer:
$315
Step-by-step explanation:
You are going to want to use the simple interest formula for this. The one below is modified for solving the interest earned.

<em>I = interest amount</em>
<em>P = principal amount</em>
<em>r = interest rate (decimal form)</em>
<em>t = time</em>
<em />
Now we can plug in the values into the equation:


This means that Rachel earned $315 worth of interest in the 15 year period.
Answer:
Step-by-step explanation:
This is a related rates problem from calculus using implicit differentiation. The main equation is going to be Pythagorean's Theorem and then the derivative of that. Pythagorean's Theorem is
where c is the hypotenuse and is a constant. Therefore, the derivative of this with respect to time, and using implicit differentiation is
and dividing everything by 2 to simplify a bit:
. Upon analyzing that equation, it looks like we need values for x, y,
, and
. And here's what we were given:
and
In the greater realm of things, that's nothing at all.
BUT we can use the right triangle and the angle we were given to find both x and y. The problem we are looking to solve is to
Find
at the instant that
= .5.
Solving for x and y:
and
6tan45 = x ( and since this is a 45-45-90 triangle, y = x):
so
and now we can fill in our derivative. Remember the derivative was found to be
so
and
and
and multiplying by the reciprocal of the left gives us:
so

Add 10 + 10 + 6 + 6 = 32
32 ft.
Answer:
(2 1/4, 1 1/2) A
(-1 1/4, 1 1/2) B
(-2 1/2, 1/4) C
Step-by-step explanation:
We can determine that each tick mark represents 1/4 based off the given numbers. Now we just determine the points.
(2 1/4, 1 1/2) A
(-1 1/4, 1 1/2) B
(-2 1/2, 1/4) C
90 x 60 = 5400 is the answer