What is the X-INTERCEPT (x, 0) of the equation x - 3y = 7

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

Trent wants to buy 2 packs of trading cards for 3 dollars each. the trading card packs that trent normally buys tend to come in packs of 6, 10, 12, or 15 cards. after selecting 2 packs, trent found that the first pack of cards cost 25 cents per card, and the second pack cost 30 cents per card. trent uses this information to write the equations below in order to compare c, the number of cards in each pack.

What else equals 42 and 30 for multiply