10/5/2013Multiplication Rule 11  Multiplication Rule 1: If a > b and c > 0 then a c > bc Examples If 7 > 3 and 5 > 0 then 7(5) > 3(5) If 2x + 6 > 8 then ½(2x + 6) > ½(8) Inequality Rules … an equivalent inequality OR x + 3 > 4

10/5/2013Multiplication Rule 12 Inequality Rules Example If x > 2 then x 2 > 4 Note that x > 2 and 2 > 0 From transitive property of > Applying Rule 1 to x > 2 we have x x > 2 x WHY ? x 2 > 2xOR x > 2 > 0 x > 0

10/5/2013Multiplication Rule 13 Inequality Rules Example If x > 2 then x 2 > 4 x x > 2 x Applying Rule 1 again to x > 2 we have x 2 > 2 2 From the transitive property of > x 2 > 2xOR x 2 > 4 2x > 4 x 2 > 2x > 4 In General: If | a | > | b | then a 2 > b 2