11-2 Solving Multistep Equations Course 2 Warm Up Warm Up Problem of the Day Problem of the Day Lesson Presentation Lesson Presentation

Learn to solve multistep equations. Course Solving Multistep Equations

Levi has half as many comic books as Jamal has. If you add 6 to the number of comic books Jamal has and then divide by 7, you get the number of comic books Brooke has. If Brooke has 30 comic books, how many comic books does Levi have? To answer this question, you need to set up an equation that requires more than two steps to solve. Course Solving Multistep Equations

Solve 12 – 7b + 10b = 18. Additional Example 1: Solving Equations That Contain Like Terms 12 – 7b + 10b = b = 18 – 12 3b = 6 3 b = 2 Combine like terms. Subtract 12 from both sides. Divide both sides by 3. Course Solving Multistep Equations

Solve 14 – 8b + 12b = – 8b + 12b = b = 62 – 14 4b = 48 4 b = 12 Combine like terms. Subtract 14 from both sides. Divide both sides by 4. Try This: Example 1 Course Solving Multistep Equations

Sometimes one side of an equation has has a variable expression as the numerator of a fraction. With this type of equation, it may help to first multiply both sides of the equation by the denominator. Course Solving Multistep Equations

Solve Additional Example 2: Solving Equations That Contain Fractions 3y – 6 7 = 3. 3y – 6 7 = (7)3 (7) 3y – 6 = y = y = 9 Multiply both sides by 7. Add 6 to both sides. Divide both sides by 3. Course Solving Multistep Equations

Solve 4y – 4 8 = 14. 4y – 4 8 = (8)14 (8) 4y – 4 = y = y = 29 Multiply both sides by 8. Add 4 to both sides. Divide both sides by 4. Try This: Example 2 Course Solving Multistep Equations

Troy has three times as many trading cards as Hillary. Subtracting 9 from the number of trading cards Troy has and then dividing by 6 gives the number of cards Sean has. If Sean has 24 trading cards, how many trading cards does Hillary own? Additional Example 3: Problem Solving Application Course Solving Multistep Equations

Additional Example 3 Continued 1 Understand the Problem Rewrite the question as a statement. Find the number of trading cards that Hillary has. List the important information: Troy has 3 times as many trading cards as Hillary has. Subtracting 9 from the number of trading cards that Troy has and then dividing by 6 gives the number cards Sean has. Sean has 24 trading cards. Course Solving Multistep Equations

2 Make a Plan Let c represent the number of trading cards Hillary has. Then 3c represents the number Troy has, and 3c – 9 6 represents the number Sean has, which equals 24. 3c – 9 6 Solve the equation = 24 for c to find the number of cards Hillary has. Additional Example 3 Continued Course Solving Multistep Equations

Solve 3 3c – 9 6 = 24 3c – 9 6 = (6)24(6) 3c – 9 = 144 3c – = c = c = 51 Hillary has 51 cards. Multiply both sides by 6. Add 9 to both sides. Divide both sides by 3. Additional Example 3 Continued Course Solving Multistep Equations

Look Back 4 If Hillary has 51 cards, then Troy has 153 cards. When you subtract 9 from 153, you get 144. And 144 divided by 6 is 24, which is the number of cards that Sean has. So the answer is correct. Additional Example 3 Continued Course Solving Multistep Equations

Try This: Example 3 Insert Lesson Title Here John is twice as old as Helen. Subtracting 4 from John’s age and then dividing by 2 gives William’s age. If William is 24, how old is Helen? Course Solving Multistep Equations

Try This: Example 3 Continued Insert Lesson Title Here 1 Understand the Problem Rewrite the question as a statement. Find Helen’s age. List the important information: John is 2 times as old as Helen. Subtracting 4 from John’s age and then dividing by 2 gives William’s age. William is 24 years old. Course Solving Multistep Equations

Try This: Example 3 Continued Insert Lesson Title Here 2 Make a Plan Let h stand for Helen’s age. Then 2h represents John’s age, and 2h – 4 2 which equals 24. represents William’s age, 2h – 4 2 Solve the equation = 24 for h to find Helen’s age. Course Solving Multistep Equations

Try This: Example 3 Continued Insert Lesson Title Here Solve 3 2h – 4 2 2h – 4 2 = 24 = (2)24 (2) 2h – 4 = 48 2h – = h = h = 26 Helen is 26 years old. Multiply both sides by 2. Add 4 to both sides. Divide both sides by 2. Course Solving Multistep Equations

Try This: Example 3 Continued Insert Lesson Title Here Look Back 4 If Helen is 26 years old, then John is 52 years old. When you subtract 4 from 52 you get 48. And 48 divided by 2 is 24, which is the age of William. So the answer is correct. Course Solving Multistep Equations