Ineed someone to teach me how to do at least half of these problems

Here, You need to substitute the value of x, and y, in the equation then check if L.H.S is equal to R.H.S or not. If they are equal then, ordered pair was correct, otherwise they are not applicable.

75) Here, oly option D can fit i the equation, we can check:
 3(-5) -2(-1) = -15+2 = -13 = R.H.S
So, the pairs are valid.

76) Here, only option D is your answer, 
4(2) - 4 = 8 - 4 = R.H.S

Do the same thing in every equation!

Hope this helps!