# Understanding MLR [closed]

I am just trying to explain to people with very little knowledge of statistic about MLR.

I basically Have this question:

1. Why when we have the number of independent variable ($X$) and dependent variable ($y$) the same then it will be full rank and we will have unique LS solution?

2. Why should we do $(X'X)-1 X'Y$? Why not simply $X'Y$?

## closed as unclear what you're asking by Michael Chernick, whuber♦Jun 14 '18 at 21:09

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• What is "MLR"? If it's multiple (ordinary least squares) regression, then you will find a very great number of answers to your questions by searching our site. – whuber Jun 14 '18 at 21:09
• @whuber♦ Yes multiple (ordinary least squares) can you please direct me to some of them? – nik Jun 14 '18 at 21:28
• Click on the "multiple-regression" tag you applied to this question. Consider refining that search by adding more keywords like "formula" or "rank." – whuber Jun 14 '18 at 21:30
• @whuber♦ [multiple-regression] [formula] led to nothing – nik Jun 14 '18 at 21:55
• Don't put square brackets around your search terms. There's help available from an "Advanced search tips" link at the right of your screen after you have performed an initial search. – whuber Jun 15 '18 at 13:24