Answer:
a. the investment earns 4%
b. yes
Step-by-step explanation:
The "rule of 72" says that an investment earning compound interest at x% will double in value after 72/x years. That is, ...
f(x) = 72/x
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<h3>a.</h3>
We interpret f(4) to mean Becky's friend is interested in the doubling time for an investment that earns 4% interest.
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<h3>b.</h3>
Using the above formula, ...
f(4) = 72/4 = 18
The friend's math is correct.
Gloria would have worked six hours which would put her at $72.00 but spends $0.50 to travel to and from work and that would put her at $71.50
Answer:
3 in
Step-by-step explanation:
Apparently, we are to assume that the height and width are proportional:
height/width = (6 in)/(8 in) = (new height)/(4 in)
Multiplying by 4 in will tell us the new height:
new height = (4 in)(6/8) = 3 in
The reduced frame will be 3 inches tall.
So there are two ways.
First you could solve for y and plug it into the calculator. one equation for y1 and another for y2. Then go 2nd trace and press 5 and then press enter 3 times to find the intersection.
the second way is to solve by hand. I would suggest solve the first equation for y and plug the equation solved for y into the other equation. so y = -3x + 9 and 3x-5y=15. Then you could do 3x - 5(-3x+9) = 15. Finally solve for x and plug in x into both equations to see if you get the same y value.
The answer should be (10/3, -1)
