Which ordered pairs are on the line 3x−4y=9 ?

All except coordinates (-1, 3)

isolate the y

Add 4y to both sides
3x - 4y+ 4y = 9 + 4y
3x=9 + 4y

subtract 9 from both sides

3x-9= 9-9 + 4y
3x-9=4y

divide both sides by 4

3/4(x)= 4/4(y)
3/4(x) = y

solve for y by substituting (0) for x variable.
and add this to the equation above

y= 3/4(x) - 9/4

when x = 0, y = -9/4
when x= 1, y= -6/4 or -3/2
when x = 2/3, y= -7/4
when x = -1, y= -3
when x = -5, y= -24/4 or -6

D. i think it is the savings