# 1. Ciara solved the exponential equation 3 x+1 = 15 and her work is shown below. What is the first step she did incorrectly?

1. Ciara solved the exponential equation 3x+1 = 15 and her work is shown below. What is the first step she did incorrectly?

Step 1:

log 3x+1 = log15

Step 2:

(x + 1)log 3 = log15

Step 3:

log3 =

Step 4:

0.477121 =

Step 5:

0.477121(x + 1) = 1.176091

Step 6:

x + 1 =

Step 7:

x + 1 = 2.464975

Step 8:

x = 1.464975

2. A motorcycle cost \$12,000 when it was purchased. The value of a motorcycle decreases by 6% each year. Find the rate of decay each month and select the correct answer below.

a)  −0.005143%

b)  −0.5143%

c)  −0.5%

d)  −0.005%

3. You decide to put \$150 in a savings account to save for a \$3,000 down payment on a new car. If the account has an interest rate of 2.5% per year and is compounded monthly, how long does it take you to earn \$3,000 without depositing any additional funds?

a)  10.1101 years

b)  119.954 years

c)  121.321 years

d)  134.34 years