Which pair shows equivalent expressions?

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

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.

Which of the following is best modeled using a linear equation y=ax+b, where a is less than 0?