1. The problem states that the total cost $y$ including the protection plan is given by the equation $$y = 1.2x$$ where $x$ is the cost of the computer alone. 2. Nathan pays a total of $719.70, so we substitute $y = 719.70$ into the equation: $$719.70 = 1.2x$$ 3. To find $x$, divide both sides by 1.2: $$\frac{719.70}{\cancel{1.2}} = \frac{1.2x}{\cancel{1.2}}$$ 4. Simplifying the left side: $$x = \frac{719.70}{1.2}$$ 5. Calculate the division: $$x = 599.75$$ 6. Therefore, the cost of the computer before adding the protection plan is $599.75$.