Me asap answer c and d for 4 is y= x/2 -1 and y= x/2-2

Use the data in the given table for #4 to find the slope of the line through these four points.  I did this this way:
         5-3        2
m = = = 1/2
        12-8        4

Now use y = mx + b to determine the y-intercept:

Borrowing the coefficients (0,0) from the table,

0 = (1/2)(0) + b.  Thus, b = 0, and y = (1/2)x (answer)