Question 200650
 X^2+12x+32/X+4*3/x+8
If you mean
{{{((x^2+12x+32)/(x+4))*(3/(x+8))}}}
= {{{((x+4)*(x+8)/(x+4))*(3/(x+8))}}}
One step at a time, cancel the (x+4) terms.
= {{{((x+8)*3/(x+8))}}}
Cancel the (x+8)'s
= 3
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2. 21x^2z^3/6y^3/7xz^3/2y^4 
Is it 21x^2z^3/6y^3 divided by 7xz^3/2y^4 ??
Reduce it some first.
21x^2z^3/6y^3 divided by 7xz^3/2y^4
= {{{(7x^2z^3/2y^3)/(7xz^3/2y^4)}}}
Invert the 2nd fraction and multiply
= {{{(7x^2z^3/2y^3)*(2y^4/7xz^3)}}}
You can either multiply, then cancel, or cancel some terms here.
I'll multiply first.
= {{{14x^2y^4z^3/14xy^3z^3}}}
= xy