Q:

Fontsize for text vs. math

Disclaimer: I am new to Latex, I apologize for the lack of specific and correct vocabulary to describe my question.
I am building an equation sheet and have a question about font sizes.  
I would like to specify the font size for the text to be smaller than the font size for the equations.  
I know I can do this by brute force (1st table), but that seems cumbersome and inelegant.  
When I set the font size for the whole table the size of the equations also change (2nd table). 
Is there any way to achieve the effects of the 1st table without defining the size of every text string? 
Thank you!

\documentclass[table,9pt]{extarticle}
\usepackage[a4paper, landscape]{geometry}
\everymath{\displaystyle}

\begin{document}

\begin{tabular}{lll}
    $\frac{N(x)}{(ax+b)(cx+d)}$ & \small{Linear Factors}    & $\frac{A}{ax+b}+\frac{B}{cx+d}$\\ [3.5ex]
    $\frac{N(x)}{(ax+b)^2}$     & \small{Repeated}      & $\frac{A}{ax+b}+\frac{B}{(ax+b)^2}$\\[10ex]
\end{tabular}       

\small{

    \begin{tabular}{lll}
        $\frac{N(x)}{(ax+b)(cx+d)}$ & Linear Factors    & $\frac{A}{ax+b}+\frac{B}{cx+d}$   \\  [3.5ex]
        $\frac{N(x)}{(ax+b)^2}$     & Repeated          & $\frac{A}{ax+b}+\frac{B}{(ax+b)^2}$\\ 
    \end{tabular}       
    }

\end{document}

A:

Just one approach: Make the column use smaller text (\tiny here for the sake of showing a clear difference).
And please note: Use font size commands within the group they should resize.

\documentclass[table,9pt]{extarticle}
\usepackage[a4paper, landscape]{geometry}
\everymath{\displaystyle}

\usepackage{array}

\begin{document}

    \begin{tabular}{lll}
        $\frac{N(x)}{(ax+b)(cx+d)}$ & {\small Linear Factors}    & $\frac{A}{ax+b}+\frac{B}{cx+d}$\\ [3.5ex]
        $\frac{N(x)}{(ax+b)^2}$     & {\small Repeated}      & $\frac{A}{ax+b}+\frac{B}{(ax+b)^2}$\\[10ex]
    \end{tabular}       

    \begin{tabular}{l>{\tiny}ll}
        $\frac{N(x)}{(ax+b)(cx+d)}$ & Linear Factors    & $\frac{A}{ax+b}+\frac{B}{cx+d}$   \\  [3.5ex]
        $\frac{N(x)}{(ax+b)^2}$     & Repeated          & $\frac{A}{ax+b}+\frac{B}{(ax+b)^2}$\\ 
    \end{tabular}           

\end{document}

