For this case we have the following equation:
Rewriting we have:
For expressions to be equal, exponents must be equal. So:
To factor, we look for two numbers that, when multiplied, result in -3 and when added, result in -2. These numbers are -3 and 1.
Thus, the roots are:
Answer:
The annual interest rate is 3.5%.
Solution:
Given Interest (I) = $26.25
Principal (P) = $500
Time (t) = 18 months
Rate of interest (r) = ?
Time must be in years to find the rate per annum.
1 year = 12 months
Divide the time by 12.
Time (t) = years
Now, find the rate of interest using simple interest formula.
<u>Simple interest formula:</u>
⇒ r = 3.5%
Hence the annual interest rate is 3.5%.
