The formula for the future value vv (in dollars) of an investment earning simple interest is v=p+prtv=p+prt, where pp (in dollars) is the principal, rr is the annual interest rate (in decimal form) and tt is the time (in years). a. solve the formula for pp.

The future value of the investment in dollars s
V = p + prt
where 
p = principal, dollars
r = annual interest rate (in decimal form)
t = time, years

To determine p, write the formula as follows:
Factorize p out on the right side.
  V = p(1 + rt)
Divide each side b (1 + rt).