It is given that the circuit overloads at 1800 watts of electricity and that the microwave oven uses 1000 watts. Let's call the number of additional watts we can use without overloading the circuit w. Since the total amount of watts of electricity used should be less than 1800, we can write the following inequality:
1000+w<1800.
Let's solve this inequality by subtracting 1000 from both sides.
We determined that we can use less than 800 watts without overloading the circuit. Since the toaster needs 800 watts to work and we have less than that at our disposal, we cannot plug the toaster into the circuit without it overloading.
