Which ordered pair in the form (a, b) is a solution of this equation?

7a - 5b = 28

1. 0,4

2. 4,0

3. - 3,-2

4. - 2,-3

You can figure out the answer to this by plugging in each set of coordinates into the equation and solving.

7a - 5b = 28 Plug in the coordinates

1. 7 (0) - 5 (4) = 28 Multiply

0 - 20 = 28 Subtract

-20 ≠ 28

2. 7 (4) - 5 (0) = 28 Multiply

28 - 0 = 28 Subtract

28 = 28

3. 7 (-3) - 5 (-2) = 28 Multipy

-21 - - 10 = 28 Simplify the double negative

-21 + 10 = 28 Add

-11 ≠ 28

4. 7 (-2) - 5 (-3) = 28 Multiply

-14 - - 15 = 28 Simplify the double negative

-14 + 15 = 28 Add

1 ≠ 28

As you can see, the only set of coordinates that worked was 2. (4, 0).