What's the scientific notation for 420

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

Which of the following is the result of expanding the series

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*