How do you solve this system by elimination?

-5x+7y=11
-5x+3y=19

i don't know how to solve it.

Shiny white dental insurance costs $258 per year. approximately one-third of insured people need a filling, which averages $110 each. 80% of insured people get a preventive check-up each year, and the average cost of this visit is $95. if you consider shiny white’s income and expenses, what is the expected value of each insured customer?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin. how many doctors use brand x aspirin

Roy has 4 1/2 pizzas for the soccer team to split after the game. if each member is going to get 1/2 of a pizza, how many players are on the soccer team