How much greater was the mass of the third rock than the combined mass of the other two rocks

Can some one explain this i got sent this. is this a threat i’m scared

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?

Find │7│. a. 1 over 7 b. –7 c. 7 asap i always mark brailiest who me so