For this problem, the numbers can be plugged back into the simple interest rate formula: I = (P)(r)(t) I is the interest P is the principal/initial value r is the interest rate t is the time (in years)
-Jack's investment is the principal/initial value. -The interest is rate is 0.03 (decimal form) -The time in years is 6 years. -Jack earned $972 Plug these values in and you get: $972 = (P)(0.03)(6) Now solve for P: Multiply 0.03 and 6 $972 = (P)(0.18) Divide both sides by 0.18 $972/0.18 = (P)/(0.18) You would end up with $5400 = P
