1. Sec 2-5 Concept: Reasoning with Properties from Algebra
Objective: Given properties from Algebra, justify segment and angle relationships as measured by a s.g

2. c+cr = n -c -c cr = n-c c c r = n-c c
Example 1: Pay Raises. Suppose your receive a pay raise at work. You can calculate your percent increase by using the pay raise formula c(1+r) = n, where c is your current wage (in dollars per hour), r is your percent increase (as a decimal) and n is your new wage ( in dollars per hour)
Solve the formula for r and write a reason for each step
C(1+r) = n
Given
c+cr = n
Distributive Property
-c c
cr = n-c
Subtraction Property
c c
r = n-c c
Division Property

3. Example 1 cont. : Pay Raises. Suppose your receive a pay raise at work
Example 1 cont.: Pay Raises. Suppose your receive a pay raise at work. You can calculate your percent increase by using the pay raise formula c(1+r) = n, where c is your current wage (in dollars per hour), r is your percent increase (as a decimal) and n is your new wage ( in dollars per hour)
Use result from the previous page to find your percent increase if you current wage is $10.00 and your new wage will be $10.80
r = n-c c r=
10.00
r= .08 or 8%

4. Example 2: Use the property to complete the statement
1. Transitive Property of Equality: If BC=CD and CD = EF, then _______
BC = EF
2. Subtraction Property of Equality:
If PQ+ST=RS+ST then, ________
PQ = RS

5. Example 3: Solve the equation and state a reason for each step
Given
q= 4
Subtraction property

6. Example 3cont: Solve the equation and state a reason for each step
-2(-w+3)=15
Given
2w-6 =15
Distributive Property
+6 +6
2w = 21
Addition Property
w = 10.5
Division Propery

7. Example 4

8. Example 5 Show that the perimeter of triangle ABC is equal to the perimeter of triangle ADC
Reason:
Equation:
Explanation:
AD = CB
DC=BA
AC=AC
AD+DC=CB+DC
AD+DC=CB+BA
AD+DC+AC=CB+BA+AC

9. Today’s Work
In Class:
HW: