Means, for every 1 input, there is 1 coresponding output
normally x is input and y is output in form (x,y)
so just look for the option(s) that has/have every first number repeat with only 1 2nd number
A. -7 repeats with 5 and -3, not a function
B. no repeats of first number (6,-8) and (-5,-8) are fine because first numbers don't repeat, das is funciton
C. no repeats, function
D. no repeats, function
answer is B,C,D
        
             
        
        
        
1.D 2. A 3.C 4.D
1 Is the monomial as it only contains one expression.
2. Is the difference of squares because something squared minus something squared.
3. Is standard because it is of the form

4. We know D is the not the monomial simply because its power is negative which means it does not fit the definition of a polynomial.