Question 19214
Hello There:

Substitute the values in the ordered pair for their corresponding variables in the equation.  Then do the arithmetic with the equation to see if you end up with a true statement.

For example, let's use the standard variable names for the ordered pair (x, y).

Here is an equation containing x and y:

3*x + 7*y = -4

Here is a given ordered pair:

(2, 1)

We substitute 2 for x and 1 for y in the equation.

3*2 + 7*1 = -4

Now do the arithmetic to simplify.

6 + 7 = -4

13 = -4

We ended up with a false statement, so we can say that the ordered pair of coordinates (2, 1) is not a solution to the equation.

Here's another pair of coordinates:

(1, -1)

Substituting, we get the equation:

3*1 + 7*(-1) = -4

3 - 7 = -4

-4 = -4

This is a true statement, so the ordered pair (1, -1) is a solution.

~ Mark