Question 596429
<pre>

No answer because:

1.  You posted more than two problems.

2.  You must learn to use parentheses, because there 
    is no way to tell which if any of the following
    which this:

6x+6÷5÷9x+9÷10

means:

{{{6x+(6/(5/9x))+(9/10)}}}
or
{{{(6x+6/5)/(9x+9)/10}}}
or
{{{6x+6/(5/9x+9)/10}}}
or
{{{(6x+6)/5/(9x+9/10)}}}
or
{{{6x+(6/5)/9x+(9/10)}}}
or
{{{((6x+6)/5)/9x+(9/10)}}}
or
{{{6x+((6/(5/9x))+(9/10))}}}
or
{{{(6x+6)/5/(9x+9)/10}}}

Edwin</pre>