math question on simplest form?

Question

these are the problems.......
#1) combine and express in simplest form:

y - 20 2
-------------- + --------
y^2 - 16 y - 4

#2) expressed in simplest form,

x^2 = x - 6 x + 2
------------------ * -------------- , x does not = 2, o, -2,is equivalent to?
x^2 - 4 x + 3



my question is for the multiplying do you factor and simplify and for adding you factor then combine?? how can u tell when and wat to do?

Answer 1

the key to adding is common denominators:

y - 20 ..............2
-------------- + --------- =
(y+4)(y-4) .....y - 4

y - 20 ..............2(y+4)
-------------- + ---------------- =
(y+4)(y-4) ..... (y-4)(y+4)

y - 20 + 2y + 8
----------------------- =
(y+4)(y-4)

3y - 12
------------ =
(y+4)(y-4)

3(y - 4)
------------ =
(y+4)(y-4)

3
------ =
y+4

the essence of multiplying is factoring and cancelling (top to bottom) common factors. but your #2 isn't quite readable. try using ....... to provide spacing, or be VERY meticulous in using parentheses.