Posted by Iz on .
x^2x12/x^23x4*x^21/x^2+2x3
Please help me solve, I am desperate!

Math 
Mike,
When simplifying rational expressions you need to factor all the numerators & denominators (if possible):
x^2x12 > (x4)(x+3)
x^23x4 > (x4)(x+1)
x^21 > (x+1)(x1)
x^2+2x3 > (x+3)(x1)
Therefore you will have:
(x4)(x+3)*(x+1)(x1)
(x4)(x+1) (x+3)(x1)
You can then cancel out all common factors that appear on top and bottom. If you notice, for every factor on top, there is a match on the bottom. THus, everything cancels out leaving you with a final answer of 1!