To find the value of y, we must substitute x with 10 in the equation.
5x - y = 54
5(10) - y = 54
Simplify
50 - y = 54
Move 50 to the right side. After moving to other side, it becomes negative.
50 - y = 54
- y = 54 - 50
- y = 4
----------------------- divide both side by -1
y = -4
The value of y is -4
