This in what I got:
(-7i)(10i)
-70i
The formula we use for continuous compounding is

where P is the initial amount invested, r is the rate as a decimal, and t is time in years. Our P = 1300, our r = .042, and our t = 5.75 (9 months is 3/4 of a year, and 3/4 in a decimal is .75). Putting all that into our formula we have

. We have to multiply those 2 powers together and then raise euler's number to it, then multiply by 1300. Doing all of that, we get the amount at the end to be $1,655.10
V=(4/3)pir^3
4.5pi=(4/3)pir^3
divide both sides by pi
4.5=(4/3)r^3
times 3/4 both sides
3.375=r^3
cube root both sides
1.5=r
radius is 1.5cm
A differential equation is one that contains the derivative of a function. For example f(x) + 3 = 4f'(x) - 2. Usually you will be given one of the functions and initial conditions if you have to solve.