What is x^2-8x+7=0 in vertex form, in this form (x+_)^2=_

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

Using only the digits 5, 6, 7, 8, how many different three digit numbers can be formed if no digit is repeated in a number?