Please help Find f (-4)

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package

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?

Is the point (0, 8) on the x-axis or y-axis? how do you know?