Because we know x stays constant, draw a point on (0,5). then draw a line extending up and down from (0,5) indefinitely because no matter what y is, x always stays the same--5.
If you need to substitute the equation x = y - 1.
If you have another equation, then you would plug in y - 1 into the x value of the equation you would need to substitute into.
Hope this helps
Answer
If we had a sale price of 30% off of $1,050then the sale price is 70% of $1,050 or 0.7(1050) Then we add 7% sales tax to that making thefinal price paid 107% of [0.7(1050)] ... 1.07[0.7(1050)] = $786.45
