1. 8.2

2.  To add and subtract rational expressions, just like with fractions, you need a common denominator.  The common denominator is the LCM (Least Common Multiple) of the denominators

3. A. Find the LCM of 15a 2 bc 3, 16b 5 c 2, and 20a 3 c 6. 15a 2 bc 3 Factor the first monomial. 16b 5 c 2 Factor the second monomial. 20a 3 c 6 Factor the third monomial. LCM Use each factor the greatest number of times it appears.

4.  A. Find the LCM of 6x 2 zy 3, 9x 3 y 2 z 2, and 4x 2 z.

5. B. Find the LCM of x 3 – x 2 – 2x and x 2 – 4x + 4. LCM = Use each factor the greatest number of times it appears as a factor. x 3 – x 2 – 2xFactor the first polynomial. x 2 – 4x + 4Factor the second polynomial.

6.  B. Find the LCM of x 3 + 2x 2 – 3x and x 2 + 6x + 9.

8.  Simplify