Solve systems of equations for x + y, please!!

6x + 2y = 30
9x - 4y = 3

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Kerion has a beaded necklace business. she can make 12 necklaces is 2 hours. how long will it take her to make 9 necklaces?

Alocal restaurant advertises that the mode cost of their most popular meals is $8. if the costs of their most popular meals are $7, $8, $8, $12, $13, $15, $17, $18, and $20, which word or phrase best describes this kind of advertising? accurate inaccurate accurate, but misleading inaccurate and misleading