The real cube root is 0.03 because...
(0.000027)^1/3 = (27 x 10^-6)^1/3 = 3 x 10^-2 = 0.03
40+5=45 is written in extended form so your answer is 45
It does not say simple or compound interest.
Simple interest is rarely used these days, so assume compound.
Use the standard formula:
future value = present value*(1+rate/n)^(nt)
n=number of times interest is compounded per year (=1)
t=number of years
Plugging values,
200=100(1.09)^t
1.09^t = 2
take log
t(log(1.09))=log 2
t=log(2)/log(1.09)=0.6931/0.08618=8.04 years.
(2,1) is the solution because its where they both intersect..
Since we know that 1/4 is equal to 25%, or 0.25 in decimal form, we are able to work with 0.75 in the expression.
We are told to use j as the original price of the jeans, so we can set up the expression:

to represent the cost of the jeans with the discount.
Then to simplify, we simply take out j as a common factor, and solve what's in the parentheses:

or 
Using this equation, we can solve for the b part of the question. If the pair of jeans originally costs $60, plug in 60 to where j is in the expression:


Therefore, the cost of the jeans after the discount is C) $45.