How to graph x+y=3 and x-y=1

Ineed with number 6 , explain how to get 1978

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Consider the following estimates from the early 2010s of shares of income to each group. country poorest 40% next 30% richest 30% bolivia 10 25 65 chile 10 20 70 uruguay 20 30 50 1.) using the 4-point curved line drawing tool, plot the lorenz curve for bolivia. properly label your curve. 2.) using the 4-point curved line drawing tool, plot the lorenz curve for uruguay. properly label your curve.