8.5 Solving Equation with Variables on Each Side

X Finds His Value

• http://youtu.be/J2TYyUftI8k

1) Collect like terms2) Move variables to same side of

equation. (using the Add/ sub prop of =)

3) Move the constant to the opposite side of the equation (using the Add/ sub prop of =)

4) Solve for x (using the Mult/div prop of =)

Steps to solve multi-step linear equations

2x – 2 = -3x + 3

5x – 2 = + 3

+ 3x+ 3x

5 5x

1x

Example 1:

Example 2:

4x 4x

x 5

4 7 9 18x x

7 5 18x 18 18

25 5x 5 5

6m +5 – 2m = 10 – 3m +16

+3m+3m

4m +5 = 26 – 3m

7m +5 = 26 -5-5

7m = 21 7

1

7

1

m =3

Example 3:

Example 4: -2.2 +0.3z = 3- 0.5z -0.8z

-2.2 +0.3z = 3 - 0.5z - 0.8z-2.2 + 0.3z = 3 – 1.3z

+1.3z+1.3z

-2.2 +1.6z=3

+2.2 +2.2

1.6z=5.2

1.6 1.6 z=3.25

Example 5:1 2 1 3 3

8 5 2 8 4m m m m

1 2 4 3 6

8 5 8 8 8m m m m

5 2 9

8 5 8m m

5

8m

5

8m

2 4

5 8m 2 1

5 2m2

1

2

1

4

5m

Netflix charges a yearly membership fee of $50 plus $1.99 per DVD rental. The Blockbuster store has no membership fee and charges $3.99 per DVD rental. Write an equation and solve to find the number of

DVD’s for which the cost of each would be the same.

• # of DVD’s = x• Netflix: 50 + 1.99x • Blockbuster: 3.99 x

50 1.99 3.99x x 1.99x 1.99x

50 2.00x22

25 x

Assignment:Page 358 (2-28) even