ALGEBRA – LESSON 90 Word Problems with Two Statements of Equality Lessosn 89 Lesson 81 ALGEBRA – LESSON 90 Word Problems with Two Statements of Equality Be ready to grade the homework! 1 1 1

Anytime you are given enough information to write more than 1 equation, you are solving a system of equations. Once again, there is nothing new in the lesson that you don’t already know how to do. The key is to concentrate on writing your equations correctly.

Equality Problems The sum of two numbers is two hundred fifteen. Their difference is seventy-five. What are the numbers? L + S = 215 L – S = 75 2L = 290 L = 145 145 + S = 215 S = 70 #1

Equality Problems A potted tree weighs 26 pounds. The pot weighs 4 pounds more than the tree. How much would the pot weigh if it were empty? P + T = 26 P = T + 4 T + (T + 4) = 26 2T = 22 T = 11 P = 11 + 4 P = 15 #2

Equality Problems The sum of the ages of Petra and her mother is 55. Her mother is 7 years more than twice as old as Petra. How old are Petra and her mother? P + M = 55 M = 2P + 7 P + (2P + 7) = 55 3P = 48 P = 16 M = 2(16) + 7 M = 39 #3

Equality Problems While traveling in France, Gwenyth carefully peeked into her wallet and found that she has $105 in $10 and $5 bills. If there were 3 fewer $10 bills than $5 bills, how many of each did she have? 10NT + 5NF = 105 NT = NF – 3 10(NF – 3 ) + 5NF = 105 10NF – 30 + 5NF = 105 15NF = 135 NF = 9 NT = 9 – 3 NT = 6 #4

Homework: Problem Set 90 – Skip #6 Lesson 81 Lessosn 89 Homework: Problem Set 90 – Skip #6 7