What the answer to this 15x when x=3

Consider the function f(x)=-5x+3 what is f(-2)

Suppose that in 2008 , 840,800 citizens died of a certain disease assuming the population of teh country is 399 miliion, what is the mortality rate in units of deaths per 100,000 people?

Will give brainliest, 5/5 rank and use the function rule, y=2x +5, to find the values of y when x=1,2,3, and 4. write the answer as ordered pairs that would be used to graph the function.