This equation need help on

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.

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

How is working backward similar to solving an equation?