Download solving two step equations

Solving Two-Step Equations
Objectives:
…to solve two-step equations involving whole numbers
Assessment Anchor:
Not Available at this time.
NOTES
***EQUATIONS ARE LIKE SEE-SAWS, AND MUST REMAIN BALANCED!!
To solve a two step equation:
1. Locate the variable in the equation
2. Use the inverse (opposite) operation on both sides of the equation
a) FIRST use addition or subtraction to isolate the variable part
b) SECOND use multiplication or division to isolate the variable
3. Show your answer
EXAMPLES
1)
Add 7 on both sides
Divide by 2 on both sides
2x – 7 = 15
3x – 12 = 18
2x – 7 = 15
+7 +7
2x = 22
2
2
3x – 12 = 18
x = 11
3x =
x=
Solving Two-Step Equations
2)
Subtract 10 on both sides
Divide by 4 on both sides
3)
Subtract 19 on both sides
Multiply by 7 on both sides
4)
4x + 10 = 34
5x + 13 = 33
4x + 10 = 34
– 10 – 10
4x = 24
4 4
x=6
5x + 13 = 33
x + 19 = 24
7
x + 40 = 51
2
x + 19 = 24
7
– 19 – 19
7•x=5•7
7
x = 35
9 = x – 12
3
Add 12 on both sides
Multiply by 3 on both sides
9 = x – 12
3
+ 12
+ 12
3 • 21 = x • 3
3
63 = x
5x =
x=
x + 40 = 51
2
x=
2
x=
4=x–9
5
4=x–9
5
=x
5
=x
MORE EXAMPLES
2x – 13 = 49
x – 10 = 2
6
18 + 5k = 73