Question 870926
This question is about the Multiplication Property of Equality.
<pre>
{{{x/(-9)}}}{{{""=""}}}{{{-3}}}

{{{-9(x/(-9))}}}{{{""=""}}}{{{-9(-3)}}}
</pre>
How does the -9 outside of the ( ) reduce (x/-9) to x?
Shouldn't it be -9(-9)=81? 
<pre>
No, because the {{{-9}}} is the same thing as the fraction {{{(-9)/1}}}

So it's the same as

{{{expr((-9)/1)(x/(-9))}}}{{{""=""}}}{{{-9(-3)}}}

And then the -9 in the the numerator cancels with the -9
in the denominator, like this:

{{{expr((cross(-9))/1)(x/(cross(-9)))}}}{{{""=""}}}{{{-9(-3)}}}

And then we only have

{{{x/1}}}{{{""=""}}}{{{-9(-3)}}}

which is just x

{{{x}}}{{{""=""}}}{{{-9(-3)}}}

{{{x}}}{{{""=""}}}{{{27}}}

Edwin</pre>