(5,-3); 4x - 7y = 3
The point (5,-3) is a cordinate point (x,y). There fore x = 5 and y = -3. Therefore I can plug in 5 and -3 for x and y.
4(5) - 7(-3) = 3
20 - -21 = 3
41 = 3
Since 41 does not equal 3 the cordinate point (5,- 3) is not a solution to the equation