division equations
TRANSCRIPT
2-8 Division Equations
Course 1Course 1
2-8 Division Equations
Course 1
Warm UpWarm Up
Lesson PresentationLesson Presentation
Problem of the DayProblem of the Day
2-8 Division Equations
Course 1
Warm UpSolve.
1. 5x = 20
2. 7n = 84
3. 18 = y – 4
4. 21 = n + 3
x = 4
n = 12
y = 22
n = 18
Course 1
2-8 Division Equations
Course 1
2-8 Division Equations
Course 1
Problem of the Day
If 11 is 4 less than 3 times a number, what is the number?5
2-8 Division Equations
Course 1
Learn to solve whole-number division equations.
2-8 Division Equations
Course 1
Multiplication is the inverse of division. When an equation contains division, use multiplication to “undo” the division.
2-8 Division Equations
Course 1
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
x7
= 5
x is divided by 7. x7
= 5
7 x7
= 7 5
Check x7
= 5 357
= 5?
2-8 Division Equations
Course 1
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
p6
13 =
6 p6
6 13 =
p is divided by 6. p6
13 =
Check p6
13 =
? 786
13 =
2-8 Division Equations
Course 1
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
x2
= 9
x is divided by 2. x2
= 9
2 x2
= 2 9
Check x2
= 9 182
= 9?
2-8 Division Equations
Course 1
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
p4
72 =
4 p4
4 72 =
p is divided by 4. p4
72 =
Check p4
72 =
? 2884
72 =
2-8 Division Equations
Course 1
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 pine3
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 h3
3 14 =
Substitute 14 for height of aspen. h is divided by 3.
h3
14 =
The pine tree is 42 feet tall.
2-8 Division Equations
Course 1
Check It Out: Example 2
Let w represent her father’s weight.
190 = w
Multiply both sides by 2 to undo the division.
2 w2
2 95 =
Substitute 95 for Jamie’s weight. w is divided by 2.
w2
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
Course 1
1. = 7
2. 8 =
3. = 11
4. = 7
Lesson Quiz
5. The area of Sherry’s flower garden is one-fourth the area of her vegetable garden. Thearea of the flower garden is 17 square feet. Let xrepresent the area of her vegetable garden. Findthe area of her vegetable garden?
x = 70
x = 32
x = 99
x = 105
68 square feet
x 4
x 9
Solve each equation. Check your answers.
x 10
x 15