Section+12.2-+Rational+Expressions

__Section 12.2- Rational Expressions__
__Review__- Simplify

36m^6n^2/20m^3n^5 = 9m^3/5n^3

__Restrictions of Excluded Values__

 * Restrictions are numbers that make a denominator=0.

Example 1- Find the Restriction
2x/x-3 x-3=0 x=3. Because x does not equal 3, 3 is the restriction.

Example 2- Find the Restriction
3x-4/x^2+5x+6(Factor First) 3x-4/(x+2)(x+3) x+2=0 x+3=0 x=-2,-3 x does not equal -2 or -3 so the restrictions are -2 and -3.

__Simplifying Rational Expressions__

 * When you simplify you must __factor__ first!

Example 3- Simplify and find Restrictions
x^2+7x+12/x^2-16= (x+3)(x+4)/(x-4)(x+4) (Simplify by removing (x+4) from the numerator and denominator) (x+3)/(x-4) x does not equal 4 or -4 so those are your restrictions. Answer= x+3/x-4 with restrictions of 4 and -4.