Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

Warm Up 1. 5x = 20 2. 7n = 84 3. 18 = y – 4 4. 21 = n + 3 x = 4 n = 12 Solve. 1. 5x = 20 2. 7n = 84 3. 18 = y – 4 4. 21 = n + 3 x = 4 n = 12 y = 22 n = 18

Problem of the Day If 11 is 4 less than 3 times a number, what is the number? 5

Learn to solve whole-number division equations.

Recall that multiplication and division are inverse operations Recall that multiplication and division are inverse operations. If an equation contains division, solve it by multiplying on both sides to “undo” the division.

Additional Example 1A: Solving Division Equations Solve the equation. Check your answer. x 7 = 5 x is divided by 7. x 7 = 5 7  x 7 = 7  5 Multiply both sides by 7 to undo the division. x = 35 Check x 7 = 5 35 7 = 5 ? Substitute 35 for x in the equation. 5 = 5 ?  35 is the solution.

Additional Example 1B: Solving Division Equations Solve the equation. Check your answer. p 6 13 = p is divided by 6. p 6 13 = 6  p 6 6  13 = Multiply both sides by 6 to undo the division. 78 = p Check p 6 13 = ? 78 6 13 = Substitute 78 for p in the equation. 13 = 13 ? 78 is the solution. 

Solve the equation. Check your answer. x 2 = 9 Check It Out: Example 1A Solve the equation. Check your answer. x 2 = 9 x is divided by 2. x 2 = 9 2  x 2 = 2  9 Multiply both sides by 2 to undo the division. x = 18 Check x 2 = 9 18 2 = 9 ? Substitute 18 for x in the equation. 9 = 9 ?  18 is the solution.

Solve the equation. Check your answer. p 4 72 = Check It Out: Example 1B Solve the equation. Check your answer. p 4 72 = p is divided by 4. p 4 72 = 4  p 4 4  72 = Multiply both sides by 4 to undo the division. 288 = p Check p 4 72 = ? 288 4 72 = Substitute 288 for p in the equation. 72 = 72 ? 288 is the solution. 

height of pine height of aspen = 3 Additional Example 2: Application At Elk Meadows Park an aspen tree is one-third the height of a pine tree. height of pine height of aspen = 3 The aspen tree is 14 feet tall. How tall is the pine tree? Let h represent the height of the pine tree. Substitute 14 for height of aspen. h is divided by 3. h 3 14 = 3  h 3 3  14 = Multiply both sides by 3 to undo the division. 42 = h The pine tree is 42 feet tall.

Jamie’s father weighs 190 pounds. Check It Out: Example 2 Jamie weighs one-half as much as her father. father’s weight Jamie’s weight = 2 Jamie weighs 95 pounds. How many pounds does her father weigh? Let w represent her father’s weight. Substitute 95 for Jamie’s weight. w is divided by 2. w 2 95 = 2  w 2 2  95 = Multiply both sides by 2 to undo the division. 190 = w Jamie’s father weighs 190 pounds.

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

Lesson Quiz Solve each equation. Check your answers. x 10 1. = 7 2. 8 = 3. = 11 4. = 7 x = 70 x 4 x = 32 x 9 x = 99 x 15 x = 105 5. The area of Sherry’s flower garden is one- fourth the area of her vegetable garden. The area of the flower garden is 17 square feet. Let x represent the area of her vegetable garden. Find the area of her vegetable garden. 68 square feet

Lesson Quiz for Student Response Systems x 5 1. Solve the equation = 15. A. x = 3 B. x = 5 C. x = 20 D. x = 75

Lesson Quiz for Student Response Systems x 7 2. Solve the equation 14 = . A. x = 21 B. x = 28 C. x = 98 D. x = 121

Lesson Quiz for Student Response Systems x 2 3. Solve the equation = 42. A. x = 40 B. x = 44 C. x = 84 D. x = 104

Lesson Quiz for Student Response Systems 3 4. Solve the equation = 30. A. y = 99 B. y = 90 C. y = 33 D. y = 27

Lesson Quiz for Student Response Systems 5. The area of Linda’s rose garden is one-ninth the area of her lawn. The area of the rose garden is 15 square feet. Let x represent the area of her lawn. Identify the area of her lawn. A. 9 square feet B. 24 square feet C. 135 square feet D. 150 square feet