Solve each system using elimination plsss help

What is a graph with a never ending line called?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?