Answer:
18.7 years
Step-by-step explanation:
This is a compound interest problem and the following variables have been given;
Principal = 4000; this is the amount o be invested
APR = 9%; this is the compound interest to be earned
Accumulated amount = 20,000
We are required to determine the duration in years. We apply the compound interest formula;
The next step is to introduce natural logarithms in order to determine n;
The number of years required is thus 18.7 years
To add the variables, add the coefficients with same variable. The expression which is equivalent to given expression is . The option 2 is the correct option.
Equivalent expression are the expression whose result is equal to the original expression, but the way of representation is different.
Given information-
The expression given in the problem is,
Let the resultant expression of the above expression is . thus,
To add the algebraic terms open the brackets first,
Separate the same variable terms,
To add the variables, add the coefficients with same variable. Thus,
Hence, the expression which is equivalent to given expression is . The option 2 is the correct option.
Learn more about the equivalent expression here;