SECTION 6 5 SOLVING LINEAR INEQUALITIES PART 2

REVIEW: SOLVE THE FOLLOWING INEQUALITIES Subtract “ 5 x” from both sides Add “

I) MULTIPLYING & DIVIDING WITH INEQUALITIES When multiplying and dividing by a positive value,

EX: SOLVE THE FOLLOWING INEQUALITIES AND DRAW A NUMBER LINE TO REPRESENT THE SOLUTION

PRACTICE: GIVEN EACH EQUATION ON THE LEFT, INDICATE WHICH NUMBER LINE ON THE RIGHT

BILL HAS TWO PHONE PLANS TO CHOOSE FROM. ROGERS CHARGES $25/MONTH AND $0. 10

HOMEWORK: P 305 #3, 5, 9, 11 - 16 © Copyright all rights reserved

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REVIEW: SOLVE THE FOLLOWING INEQUALITIES Subtract “ 5 x” from both sides Add “ 24” to both sides Divide 4 from both sides SAME ANSWER!! We subtracted “ 5 x” instead| of “ 9 x” because we want to keep the coefficient of “x” positive when dealing with inequalities © Copyright all rights reserved to Homework depot: www. bcmath. ca Subtract “ 9 x” from both sides Subtract “ 16” from both sides Divide -1 from both sides Divide 4 from both sides Suppose we didn’t keep the coefficient of “x” positive and subtracted “ 9 x” When we divide both sides by a negative value, the inequality sign will switch sides

I) MULTIPLYING & DIVIDING WITH INEQUALITIES When multiplying and dividing by a positive value, the inequality sign does not change sides Likewise, adding or subtracting a positive/negative value does not change the sides of the inequality HOWEVER, when multiplying and dividing by a negative value, the inequality sign will change sides The sign stays the same and faces left The sign also stays the same and faces right © Copyright all rights reserved to Homework depot: www. bcmath. ca The sign will change sides because it’s divided by a negative value

EX: SOLVE THE FOLLOWING INEQUALITIES AND DRAW A NUMBER LINE TO REPRESENT THE SOLUTION Subtracting a value does not change the inequality sign The sign will change sides because it’s divided by a negative value © Copyright all rights reserved to Homework depot: www. bcmath. ca

BILL HAS TWO PHONE PLANS TO CHOOSE FROM. ROGERS CHARGES $25/MONTH AND $0. 10 PER MINUTE. BELL CHARGES $10/MONTH AND $0. 15 P PER MINUTE. LET “M” BE THE NUMBER OF MINUTES. A) WRITE AN EQUATION FOR HOW MUCH EACH PLAN COSTS B) FOR HOW MANY MINUTES WILL THE PLAN FROM ROGERS BE MORE EXPENSIVE? C) AFTER HOW MANY MINUTES WILL THE PLAN FROM BELL BE MORE EXPENSIVE? B) If rogers is more expensive then: A) Cost from each plan Therefore, if you use less than 300 minutes a month, then Bell would be cheaper than Rogers. So, if you use more than 300 minutes a month then Rogers would be cheaper than Bell © Copyright all rights reserved to Homework depot: www. bcmath. ca