what is the value of the expression 9 + 4n - 1 when n = 3?\n15\n20\n36\n38

Explanation:

Step1: Substitute n = 3

Substitute $n = 3$ into $9 + 4n-1$. We get $9+4\times3 - 1$.

Step2: Perform multiplication

First, calculate $4\times3=12$. The expression becomes $9 + 12-1$.

Step3: Perform addition

Calculate $9 + 12=21$. The expression is now $21-1$.

Step4: Perform subtraction

Calculate $21-1 = 20$.

Answer:

B. 20