Ch 1.7 (part 1)

One Step (Addition & Subtraction)

Objective:

To solve one-step variable equations using the Inverse Property of Addition

DefinitionsEquationA balanced statement of equality between two expressions.

One Step Only one operation is performed (+, -, , ÷)

4 + 3 = 7

fulcrum

4 + 3 7=

Goal: Isolate the variable.

1) “Undo” the operation using the Inverse Property of Addition

a + (-a) = 0

Perform the operation to both sides of the equation!

Rules

=+

4 73+

- 3

=

47

=

4

7

4 = 7

4 + 3 7=- 3 - 3

4 4=

Perform the same operation to both sides to keep the equation balanced.

x + 6 11=

This property can be used to solve variable equations.

-6 -6

x 5=

x + 6 = 11-6 -6x = 5

Algebraic Approach

Example 1

m + 2 = 10

x - 4 = 6

m - 4 = 9

11 = x – (-2)

-2 -2m = 8

+4 +4x = 10

+4 +4m = 13

-2 -29 = x

+Example 2

Example 3

Example 4

Classwork

1) x + 7 = 3

2) 8 + y = -6

3) -4 + x = 15

4) 7 = x + 13

Classwork

5) -10 = 6 + x

6) - 4 = m + 9

7) 9 + 7 = x

8) y = 8 - 13