Question 1089861
<pre>
An easier way to do these problems than the way I showed you before
is to substitute "smart" numbers for x:

{{{cx^2 - x - 28}}}{{{""=""}}}{{{(x-4^"")(ax^"" + b)}}}

The "smart" number to substitute for x is 4.  That's because if we
are "smart", we will observe the (x-4) factor, and immediately know
that if we substitute x=4, the (x-4) will become 0, which will make 
the entire right side 0

{{{c(4)^2 - 4 - 28}}}{{{""=""}}}{{{(4-4^"")(a(4)^"" + b)}}}

{{{16c - 32}}}{{{""=""}}}{{{0)}}}

{{{16c}}}{{{""=""}}}{{{32)}}}

{{{c}}}{{{""=""}}}{{{2}}}

And we need go no further, for that's all we were asked for!

Edwin</pre>