To find the solutions (and those that are not solutions), we first need to solve the equation for y, then substitute the value of x in the resulting expression, and then get the value for y.
We can also substitute the value for x and y in the expression. Those values for which the expression is equal to 7 are a solution for the equation.
First Case: (-9, -13)
Then we have:
[tex]5(-9)-4(-13)=7[/tex]
Then, this pair is a solution.
Second Case: (-5, -9)
[tex]5\cdot(-5)-4\cdot(-9)=11[/tex]
Then, this pair is NOT a solution.
Third Case: (7, 7)
[tex]5\cdot(7)-4\cdot(7)=7[/tex]
This pair is a solution.
Fourth Case: (11, 12)
[tex]5\cdot(11)-4\cdot(12)=7[/tex]
Therefore, the ordered pair that is NOT a solution of 5x - 4y = 7 is (-5, -9) (option B).
