x + 3y - 24 = 0
a) Plug in y for x and solve for y .
y + 3y - 24 = 0
4y - 24 = 0
4y = 24
y = 6
The coordinate = (x, y) = (y, y) = (6, 6)
b) Plug in 3y for x and solve for y .
(3y) + 3y - 24 = 0
6y - 24 = 0
6y = 24
y = 4
The coordinate = (x, y) = (3y, y) = (3*4, 4) = (12, 4)
c) Plug in x + 4 for y and solve for x .
x + 3y - 24 = 0
x + 3(x + 4) - 24 = 0
x + 3x + 12 - 24 = 0
4x - 12 = 0
4x = 12
x = 3
The coordinate = (x, y) = ( x, x + 4 ) = ( 3, 3 + 4 ) = (3, 7)
The graph here verifies that these coordinates are points on the line.