几道英文数学题请教急
请帮我写出公式
1. a spacecraft countdown is at -8second.in how many seconds will the spacecraft be 15second into its flight.
2. the melvilles sell records at a flea market every saturday.on 4 saturday in june,they had a profit of$30,lost$20,lost$40,and had a profit of $60.how much was their profit or loss in june