Question

The formula A=P(1+r)^2 gives the amount A in dollars that P dollars will grow to in 2 years at interest rate R (where r is given as a decimal), using compound interest. What interest rate will cause $ 5000 to grow to $ 5304.50 in 2​ years?

Answer 1

P=presne amount=5000
A=furutre amount which you want to be 5304.50

solve for r

5304.50=5000(1+r)^2
divide both sides by 5000
1.0609=(1+r)^2
sqrt both sides (remember to get positive and negative roots)
+/-1.03=1+r
minus 1 both sides
+/-1.03-1=r

+1.03-1=r=0.03=3%
-1.03-1=r=-2.03=false, no negative percents

answer is 3%