To rewrite the equation in the form Ax + By = C, we need to isolate the variables on one side of the equation:
Original equation: y = mx + b
Subtracting mx from both sides, we get: -mx + y = b
Now, let's rearrange the equation to have the x term as the coefficient of A and the y term as the coefficient of B:
-mx + y = b
Multiply both sides by -1 to change the sign of the x term:
mx - y = -b
Lastly, let's bring the constant term to the other side by multiplying the equation by -1:
-mx + y = -b
Thus, the equation in the form Ax + By = C is:
-mx + y = -b