Question 1040167
<pre>           
You should not write:

x^2r+1 + xy + 3x^2r z^3r + 3z^3ry

because that translates as

{{{x^2r+1 + xy + 3x^2r z^3r + 3z^3ry}}}

which is not anything that will factor.

You must learn to use parentheses to show
what you mean when typing algebra all on
one line.  You should have this:

x^(2r+1)+xy+3x^(2r)z^(3r)+3z^(3r)y

for then it would be interpreted as this:

{{{x^(2*r+1)+x*y}}}{{{""+""}}}{{{3*x^(2r)*z^3r+3*z^(3r)*y}}}


Factor x out of the first two terms:

{{{x(x^(2r)+y)}}}{{{""+""}}}{{{3x^(2r)z^(3r)+3z^(3r)y}}}

Factor {{{3z^(3r)}}} out of the last two terms

{{{x(x^(2r)+y)}}}{{{""+""}}}{{{3z^(3r)(x^(2r)+y)}}}

Factor out {{{(x^(2r)+y)}}}

{{{(x^(2r)+y)(x+3z^(3r))}}}

Edwin</pre>