Question 70237
<pre>       
            -5x+3y = 11
             3x+2y = -21               </pre>

First you need to cancel out one variable so you can solve for the other, I chose x since they have opposite signs. You need to make the bottom variable of x equal to the top variable so they cancel out. You can multiply the top by 3 and the bottom by 5.
<pre>
            3(-5x+3y = 11)
             5(3x+2y = -21)               </pre>

It then becomes

<pre>
            -15x+9y = 33
             15x+10y = -105               </pre>

Now add the individual components together, for instance add -15x and 15x to get 0x and so on to get
<pre>
             0x+19y=-72       </pre>    
    
Now solve for y
{{{19y=-72}}}Divide both sides by 19.
{{{y=-72/19=-3.78947368421053}}}Approximately
<p>
Now plug this y value into either equation to solve for x
{{{3x+2(-72/19) = -21}}}
{{{3x-144/19=-21}}}Multiply by 2
{{{3x=-21+144/19}}}Add 144/19 to both sides
{{{3x=-399/19+144/19}}}Find common denominator
{{{3x=-255/19}}}Simplify
{{{x=-255/57=-4.47368421052632}}}Approximately
So x=-255/57 and y=-72/19