<span>First we define Charlene's the average time, which is (8.4 + 8.6 + 8.3 + 8.5 + 8.7 + 8.5)/6 = 8.5. Normal time is 8.5/1.1 = 7.7. Charlene is faster than normal.</span>
Convert the fraction 3/4 to decimal form to get 3/4 = 0.75
To factor out 3/4, we divide each term by 3/4 or 0.75
It might be easier to divide by 0.75 to avoid two division symbols
So (3/4)z+6 = 0.75z+6
Divide each term (0.75z and 6) by 0.75 which is what we want to factor out
0.75z/0.75 = z
6/0.75 = 8
Therefore,
0.75z+6 = 0.75*(z+8)
Note how we can distribute the 0.75 back through to each term inside (z and 8) and we'll end up with 0.75z+6 again.
The answer in fraction form is

which is 3/4 outside the parenthesis multiplied by the group (z+8)
The answer 3 would be the right answer