Please answer.

You use technology ans find a sum of 6.712e-8. write this sum in standard form

Sonia works at a sporting goods store. she earns $415 per week plus a 5.25% commission on her sales. one week, her sales are $2,200. what is her total income for the week?

Bob has some 10 pound weights and some 3 pound weights together all his ways add up to 50 pounds if x represents the number 3 pound weights and y represents the number 10 pound weight which equation can be used to find the number of each type of weight bob has