I forgot how to do these and I need help

Which term best describes the association between variables a and b

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

Hurrya vegetable garden and a surrounding path are shaped like a square that together are 11ft wide. the path is 2ft wide if one bag of gravel covers 9 square feet how many bags are needed to cover the path