Deion and Brian already had 8 shells in their shell collection. Then they went to the beach to collect even more. Deion found 9 limpet shells, 10 oyster shells, and 2 conch shells. Brian found 18 more shells than Deion did. How many shells do the pair have all together? PLS ANSWER

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

Carla was trying to decide what to do saturday evening. she has $100 available to spend for the evening. she has narrowed her choices down to these events: braves game, a concert of an artist she likes, or the georgia aquarium. admission to the braves game is $25, hot dogs cost $10, sodas cost $5. the concert costs $25 for admission, $20 for a souvernir t-shirt, and $10 for a soda. the georgia aquarium has the show of a lifetime with an all you can eat and drink that costs $100. carla does not want to take any driving chances, so in addition to the cost of the aquarium, she will also need to pay for her uber/lyft, which is $15 each way. which option should carla choose if she wants to spend the least? based on that choice, what then is carla's oppotunity cost? fully explain your answer in at least one paragraph.

Perry observes the opposite parallel walls of a room in how many lines do the plains containing the walls intersect