The answer is A. because the calculated cost is 4,565.25 and the calculated revenue is 4,767.15. This means that the revenue is greater, so that leaves the owner with a 201.90$ profit.
The answer should be less than
If b is Billy's age *now*, part A would look something like this:
b + 8
Usually, it looks a little more like x = b + 8, just because we like setting the equation to an unknown variable (usually x).
b + 8 = 21
To simplify the above equation, subtract 8 from both sides:
b = 21 - 8
OR
b = 13
We just found the answer to part C above.
I'm not going to work out part D for you (you got this), but use the subtraction sign to your benefit and replace it with a word like "ago", if you're choosing age as your word problem. You could also do the traditional candy word problem where you once had 10 jellybeans and now you have 6.... Up to you. "A" will be your "now" in that case. Have fun!
Use the formula I = Prt. Plug $2300 into P.
Plug 7.5% (decimal form is 0.075) into r.
Plug 10 into t.
Your simple interest after 10 years is $1725