Begin by substituting the points with x and y in the equation.
Here’s what we know:
(x, y) —> (2, -1)
Equation: 2 + 4(-1) = 7
We must multiply first, according to the order of operations.
4 x -1 = -4
Now, we have 2 + (-4) = 7, which is the same as 2 - 4 = 7.
2 - 4 = -2.
We now have -2 = 7.
This is incorrect, so the given ordered pairs are NOT a solution of x + 4y = 7.