Which equation has a constant of proportionality equally to 2?

Which term best describes the association between variables a and b? no association a negative linear association a positive linear association a nonlinear association a scatterplot with an x axis labeled, variable a from zero to ten in increments of two and the y axis labeled, variable b from zero to one hundred forty in increments of twenty with fifteen points in a positive trend.

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

If the scale factor between two circles is 2x/5y what is the ratio of their areas?