To determine if the ordered pair (5,4) satisfies the given equation, we just have to replace the x-value 5 into the equation and calculate the y-value, if we get 4, then the given pair satisfies the equation.
3х – Зу = 15
From this equation, we can solve for y to get:
3x - 3x - 3y = 15 - 3x
-3y = 15 - 3x
-3y/-3 = 15/-3 - 3x/-3
y = -5 + x, replacing 5 for x:
y = -5 + 5 = 0
Since we didn't get 4 for y, we can conclude that the pair (5,4) doesn't satisfy the equation