Please help i don't know and I've Been stuck​

Write an equation for the function that includes the points (1,4/5) and (2,2/3)

Mario has $14.35 left in his wallet. he spent $148.43 for tablecloths. then, he spent $92.05 for napkins. how much money did mario have in his wallet to start with?

The experience c-0.25c can be used to find the cost of an item on sale for 25% off which expression beloit equivalent to c-0.25c