Does anyone know how to do this or what is the answer

Which represents the inverse of the function f(x) = 4x? h(x) = x + 4 h(x) = x – 4 h(x) = x h(x) = x

How to do this , and can some one explain

Acaterer charges $500 plus $30 per guest to cater a wedding. walt and traci don't want to spend more than $8000 on catering. write and solve an inequality in terms of the number of guests, g, that can be invited. a) 30g ? 8000; g ? 267 b) 500g < 8000; g < 16 c) 500 + 30g < 8000; g < 250 d) 500 + 30g ? 8000; g ? 250