Simple, first change the 4.5% into 0.045
Thus,
900=0.045*n
900/0.045=0.045n/0.045
20,000=n
Thus, your answer is 20,000.
The answer is .42%
Explained
I / PT = R
I = The amount of interest paid
P = The amount paid before adding interest
T = The time (weeks, months, years)
R = Interest Rate (must move 2 decimal place to the right)
The answers is 14%
49 multiply by 14% is 6.86
42.14 + 6.86= 59
The correct answer is 42x^4-24x^3+12x^2