Warm up #1 Suppose x and y vary inversely. Write a function that models each inverse variation. Find y when x=10 1. x=1, y= x=1.2, y = 3 2.

8-4 Rational Expressions (Day 1) I <3 Los Al 2/25/16 Thurs HW: Pg. 531 #8 – 19, 27 – 29 Factor First!!!!

Objective To multiply and divide rational expressions.

8-4 Rational Expressions Factoring Reminders: 1) Start with a GCF  2x 3 – 30x = 2x(x 2 – 15) 2) Difference of Squares  x 2 – 81 = (x – 9)(x + 9) 3) Trinomials: Use X-Box  x 2 – 8x + 15 = (x – 5)(x – 3)

Hints If you see +/-, then FACTOR !!!! Cancel top to bottom Parenthesis only cancel with other parenthesis that are EXACTLY the same If signs are backwards, factor out a negative Numbers/variables outside of parenthesis can reduce

Restrictions You can not have the denominator or a problem equal zero. ProblemRestriction

Ex 1) Dividing Monomials FIRST: Can’t divide by zero! Write some restrictions: Any variable on the bottom cannot equal 0 s ≠ 0, t ≠ 0 3 2

Ex 2)Dividing Polynomials Factor First Write Restrictions Now Reduce 2

EX 3) Dividing Polynomials 2

EX 4) Dividing polynomials

EX 5) Multiplying Monomials Check both original denominators for restrictions  d ≠ 0, c ≠

EX 6) Multiplying Polynomials Factor in 4 places Restrictions on both denominators  x – 3 ≠ 0, x + 2 ≠ 0, x – 2 ≠ 0  x ≠ 3,-2,2

EX 7) Multiplying Polynomials

Homework Pg. 531 #8 – 19, 27 – 29 Factor First!!!!