Can anyone answer this with full answer? ?

"more than one answer"

This is a linear polynomials(or first degree polynomials). It is a form of y=ax+b.The line passes through (4, 5) and (2, 2), so we can build a dualistic equation:          ｛5=4k + b 
                         ｛2=2k + b
solve this equation, we can know that k=1.5 and b=-1, then the function is y=1.5x - 1, D is correct.
If y=1.5x - 1, then y-2=1.5x-1-2=1.5x-3=1.5(x-2), so A is correct, too. 
y-4=1.5x-1-4=1.5x-5, so B is incorrect.
y-5=1.5x-1-5=1.5x-6=1.5(x-4), so C is correct.                                                    Now we can know the the correct options are A,C and D                      Sorry my English expression is not very good, but hope it can help you:)

The answer is 13. To figure this out I used 10 notebooks sold as a guide. I knew the answer could not be 10, because $27.95/10 was not a number stopping in the hundredths place (or a true money amount).

I tried numbers greater than 10 using a trial and error strategy until I got to 13 notebooks sold and found that it $27.95 was divisible by 13 to get an answer between $2 and $3 ($2.15 exactly).