u/Leather-Basket4919

https://preview.redd.it/a76al181iyyg1.jpg?width=3024&format=pjpg&auto=webp&s=5fb5ff2d96146a63ff8620384ac3a2aa523bcec7

https://preview.redd.it/a3g1q281iyyg1.jpg?width=3024&format=pjpg&auto=webp&s=3d6a318d75f62440e9036502cb3978a9c1cdb969

https://preview.redd.it/7tbxh281iyyg1.jpg?width=3024&format=pjpg&auto=webp&s=ebbee35b5357c628249a9585da0a43cad0f996cd

I need to do this simple calculation for electrical engineering, and no matter the mode i cannot get this to work. I keep getting the same error. If anyone has any idea please let me know.