title: scatter plot of different color in R
body: <p>How to scatter plot the following:</p>
  
  <pre><code>  var1  var2
  1  10  2
  2  20  4
  3  30  8
  4  40  16
  5  80  32
  </code></pre>
  
  <p>I need to color var1 and var2 with difft colors. x-axis should range from 1 to 5. How can I add a line showing trend of the data?</p>