1. 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

2. 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.

3. 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

4. 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 =
P = 15 #2

5. 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

6. 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 – NF = 105
15NF = 135
NF = 9
NT = 9 – 3
NT = 6 #4

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