Solving TwoStep Equations

1
Solving Two-Step Equations

• Class 840

2
Mini-Lesson

• To solve two step equations, you need to add or
  subtract first. Then you need to multiply or
  divide.
• Example
• 6X 3 21
• 6X 3 3 21 3 Add 3 to each side
• 6X 24 Divide each side by 6
• 6
• X 4

3
Another Example

• Y 2.5 7.5
• 10
• Y 2.5 2.5 7.5 2.5 Subtract 2.5 from
  each side
• 10
• 10 (Y) 10 (5) Multiply each side by 10
• 10
• Y50

4
Work Time

• Solve each equation. Check your solution.
• 2a 7 15 2. 8 1.2c 2
• 3. 6e 12 72 4. 7f 8.4 16.8
• G 11 16 6. 4 r - 16
• 2 5

5
Another Problem

• To convert a temperature in degrees Celsius to
  degrees Fahrenheit you can use the formula F 9C
  32.
• 5
• If the outside temperature is 63 F, what is the
  temperature in degrees Celsius? Round to the
  nearest whole degree.

6
Homework

• Skills Intervention Workbook
• Page 56 7 18 and word problem 22.
• For the word problem you need to write a two step
  equation. Read the problem carefully and
  determine which is the variable. What does the
  equation equal to? Will you add or subtract? Will
  you multiply or divide?

7
Solve These Two Steps

• 7X 5.8 13.1 12X 10 -130
• In 1995 the monthly cost to use America Online
  was 9.95 (including 5 hours of usage), plus
  2.95 for each additional hour. Phil paid 30.60
  in March.
• Let x be the number of additional hours that
  Phil used. Write and solve an equation to find
  x.
• b. How many hours did Phil use America Online
  in March?