31 more than a number is 12

Acamper leaves camp on a kayak and travels 50 miles east on a river, then he ties his kayak to the bank and travels 20 miles north on a bicycle. this trip can be plotted on the coordinate plane, where the camp is the point (0, 0). the distant of the camper to the camp can be found using the distance formula. which other formula can he use? a) 502 - 202 b) 502 + 202 c) 502 - 202 d) 502 + 202

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.

Can someone check if i did this correct. it’s number 4 if you’re wondering.