Question 1146639
The sum of two numbers is 84. 
<pre>Let the smaller number be represented by x.

Then use the principle: 

<I>If a letter represents one part of a given quantity, the other part of that
given quantity is represented by "That given quantity MINUS that part".</i>

So the larger number is represented by 84-x.</pre>If twice the smaller number<pre>That's 2x</pre>is subtracted from the larger​ number<pre>That's the larger minus smaller or (84-x)-2x</pre>the result is 9.<pre>That gives the equation 

(84-x)-2x = 9</pre>Find the two numbers.<pre>Solve that for x, which will be the smaller number. Subtract from 84
to get the larger number.

You finish:

Edwin</pre>