4a+5b= when a=4 and b=1

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.

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

What describes horizontal cross section of the right rectangle 6m 8m 5m