<PRE><B>Question 121544</B>
Well this uses a system of equations so lets first come up with that system.&lt;br&gt;

Since its $6 per adult meal and $3.50 per child meal and you made $935 the first equation is:&lt;br&gt;

6a+3.50c=935&lt;br&gt;

to make the math a little easier I would multiply that by 100 to clear the decimal but you don&#39;t have to, either way it works out.&lt;br&gt;

600a + 350c = 93500&lt;br&gt;

Since 210 meals served to children and adults combined the second equation is:&lt;br&gt;

a + c = 210.&lt;br&gt;

so your system of equations is now:&lt;br&gt;

600a + 350c = 93500
a + c = 210&lt;br&gt;

now we start solving using substitution.  First solve equation one for a.&lt;br&gt;

a = 210-c&lt;br&gt;

now substitute that into equation on and solve for c.&lt;br&gt;

600a + 350c = 93500 --&gt; substitute a = 210-c in for a
600(210-c) + 350c = 93500 --&gt; Multiply
126000 - 600c + 350c =  93500 --&gt; Combine like terms
126000 - 250c = 93500 --&gt; Subtract 126000 from both sides
-250c = -32500 --&gt; divide both sides by -250
c = 130&lt;br&gt;

now that we have a value for c go back and solve for a.&lt;br&gt;

a = 210-130 = 80&lt;br&gt;

so now we know that there were 80 adults served and 130 children served at the banquet.  </PRE>