Which functions have a positive rate of change and which have a negative rate of change?
column a column b
1. 2x – 3y = 9 a. positive
b. negative
2. y = −4x + 5
3. x y
−1 −5
1 1
3 7
4. x y
1 −2
2 −6
3 −10

Ok I just did a test on this and my teacher taught me how to do it, For problem like number 3 with the table of numbers, You take the first to sets like -1,-5 and 1,1Then   you do 1 - (-5) =  your answer then 1 - (-1) = your answer than you get 6 and 2  ...you want to divided those numbers 6/2 = 3 and that is positive so #3 is positive.                                                                                                                       Same thing for #4  1,-2 and 2,-6       -6 - (-2) = x      2 - 1 = x  x/x  I want you to solve #4 for yourself        #2 is already done  y = -4x + 5  just take the -4 and -4 is negative so #2 is negative.   Then #1  I have a hard time with those but I think it's positive