You need to divide 12 by 16 to get a decimal that you can turn into a percent. 12 ÷ 16 = .75. You turn that .75 into 75%. Greg's football team won 75% of their games.
The slope-point formula:

We have (3, -5) and (-8, 4).
Substitute:

720 divided by 8 and then look up the answer to that as a fraction on Google
The 3 in the hundreds place (value of 300) has a value that is 10x the 3 in the tens (value of 30).