Answer
$7.5\% = r$
Work Step by Step
RECALL:
The formula for the future value $A$ is:
$A=P(1+rt)$
where
P = principal amount borrowed
r = interest rate per year
t = time in years
Use the formula above, with $A=\$2150$, $P=\$2000$, and $t=1$, to obtain:
$\$2150 = \$2000(1+r \cdot 1)
\\\$2150 = \$2000(1+r)$
Divide $\$2000$ on both sides of the equation to obtain:
$\frac{2150}{2000} = 1+r
\\1.075 = 1+r$
Subtract $1$ on both sides of the equation to obtain:
$0.075 = r$
Convert to percent to obtain:
$7.5\% = r$
