How to solve this problem: 1 1/2(n-4 1/2)=12

n = 25/2, or n = 12  1/2

Step-by-step explanation:

It's essential that you use parentheses here to show how your numerals are grouped.  I have made some assumptions here, and believe you meant:

(1  1/2)(n - 4  1/2) = 12.

First, convert 1  1/2 and 4  1/2 into improper fractions:

(3/2)(n - 9/2) = 12

Multiplying both sides by (2/3) eliminates the fractional coefficient (3/2):

n - 9/2 = (2/3)(12), or    n - 9/2 = 8.

Again, eliminate the fraction by multiplying all terms by 2:

2n - 9 = 16

Then 2n = 25, and n = 25/2, or n = 12  1/2

investment b is an ordinary annuity with $3,909.64 in the account after one year.

step-by-step explanation: