2-8 Division Equations Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes

2-8 Division Equations Warm Up Solve. 1. 5x = n = = y – = n + 3 x = 4 n = 12 y = 22 n = 18

2-8 Division Equations Problem of the Day If 11 is 4 less than 3 times a number, what is the number? 5

2-8 Division Equations Learn to solve whole-number division equations.

2-8 Division Equations Recall that multiplication and division are inverse operations. If an equation contains division, solve it by multiplying on both sides to “undo” the division.

2-8 Division Equations x = 35 Multiply both sides by 7 to undo the division. Substitute 35 for x in the equation. Solve the equation. Check your answer. 35 is the solution. 5 = 5 ? Additional Example 1A: Solving Division Equations x 7 = 5 x is divided by 7. x 7 = 5 7 7  x 7 = 7  5 Check x 7 = = 5 ?

2-8 Division Equations 78 = p Multiply both sides by 6 to undo the division. Substitute 78 for p in the equation. Solve the equation. Check your answer. 78 is the solution. 13 = 13 ? Additional Example 1B: Solving Division Equations p 6 13 = 6 6  p 6 6  13 = p is divided by 6. p 6 13 = Check p 6 13 = ? =

2-8 Division Equations x = 18 Multiply both sides by 2 to undo the division. Substitute 18 for x in the equation. Solve the equation. Check your answer. 18 is the solution. 9 = 9 ? Check It Out: Example 1A x 2 = 9 x is divided by 2. x 2 = 9 2 2  x 2 = 2  9 Check x 2 = = 9 ?

2-8 Division Equations 288 = p Multiply both sides by 4 to undo the division. Substitute 288 for p in the equation. Solve the equation. Check your answer. 288 is the solution. 72 = 72 ? Check It Out: Example 1B p 4 72 = 4 4  p 4 4  72 = p is divided by 4. p 4 72 = Check p 4 72 = ? =

2-8 Division Equations At Elk Meadows Park an aspen tree is one- third the height of a pine tree. Additional Example 2: Application height of aspen = height of pine 3 The aspen tree is 14 feet tall. How tall is the pine tree? Let h represent the height of the pine tree. 42 = h Multiply both sides by 3 to undo the division. 3 3  h 3 3  14 = Substitute 14 for height of aspen. h is divided by 3. h 3 14 = The pine tree is 42 feet tall.

2-8 Division Equations Check It Out: Example 2 Let w represent her father’s weight. 190 = w Multiply both sides by 2 to undo the division. 2 2  w 2 2  95 = Substitute 95 for Jamie’s weight. w is divided by 2. w 2 95 = Jamie’s father weighs 190 pounds. Jamie weighs one-half as much as her father. Jamie’s weight = father’s weight 2 Jamie weighs 95 pounds. How many pounds does her father weigh?

2-8 Division Equations Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

2-8 Division Equations 1. = = 3. = = 7 Lesson Quiz 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. x = 70 x = 32 x = 99 x = square feet x 4 x 9 Solve each equation. Check your answers. x 10 x 15

2-8 Division Equations 1. Solve the equation = 15. A. x = 3 B. x = 5 C. x = 20 D. x = 75 Lesson Quiz for Student Response Systems x 5

2-8 Division Equations 2. Solve the equation 14 =. A. x = 21 B. x = 28 C. x = 98 D. x = 121 Lesson Quiz for Student Response Systems x 7

2-8 Division Equations 3. Solve the equation = 42. A. x = 40 B. x = 44 C. x = 84 D. x = 104 Lesson Quiz for Student Response Systems x 2

2-8 Division Equations 4. Solve the equation = 30. A. y = 99 B. y = 90 C. y = 33 D. y = 27 Lesson Quiz for Student Response Systems y 3

2-8 Division Equations 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 Lesson Quiz for Student Response Systems