Question 1128472
Use the compound interest formula Upper A= P( 1 + r )^t to find the annual interest​ rate, r, if in 2 years an investment of $2,000 grows to $ 3,380.

The rate is ? %
<pre>{{{matrix(1,3, A, "=", P(1 + r)^2)}}}
{{{matrix(1,3, "3,380", "=", "2,000"(1 + r)^2)}}} ------- Substituting 3,800 for A, $2,000 for P, and 2 for t
{{{matrix(1,3, "3,380"/"2,000", "=", (1 + r)^2)}}}
{{{matrix(1,3, 169/100, "=", (1 + r)^2)}}}          OR     {{{matrix(1,3, 1.69, "=", (1 + r)^2)}}} 
{{{matrix(1,3, " "+- sqrt(169/100), "=", sqrt((1 + r)^2))}}}     OR    {{{matrix(1,3, ""+- sqrt(1.69), "=", sqrt((1 + r)^2))}}} 
{{{matrix(1,3, 13/10, "=", 1 + r)}}}              OR    {{{matrix(1,3, 1.3, "=", 1 + r)}}} ------- ONLY solution > 0 is applicable HERE
Annual interest rate, or {{{highlight_green(system(matrix(1,7, r, "=", 13/10 - 1, "=", 3/10, "=", highlight("30%")), OR, 
matrix(1,9, 1.3 - 1, "=", r, "_______", r, "=", .3, "=", "30%")))}}} 
That's all!! Nothing more, nothing less!