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Lesson 3.4 Solving Equations using Multiplication or Division Students will be able to apply multiplication or division to solve one step equation.

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Textbook Big Idea Page 106 #3-23 ODD Homework (12/7/16) Textbook Big Idea Page 106 #3-23 ODD

12. p= 2/3 2. ____ 4. ____ 6. z= 5 8. x= -18 10. w= -15.4 14. d= -5.9 Homework Solutions 12. p= 2/3 14. d= -5.9 16. x= -13.53 18. r= -1 9/20 20. k= -7 32/55 2. ____ 4. ____ 6. z= 5 8. x= -18 10. w= -15.4

Multiply & Divide Equations 1) GOAL: Get the variable on one side of the equation. 2) You always perform the same operation to both sides of an equation. 3) To undo an operation you perform its opposite operation to both sides of the equation.

Multiply & Divide Equations The inverse of add is SUBTRACT The inverse of subtract is ADD The inverse of multiply is DIVIDE The inverse of divide is MULTIPLY

Multiply & Divide Equations What you do to one side of an equation, you must do to the other side to keep it balanced. = -30 (-5)(6) Or (5)(-6)

To solve a multiplication equation Multiply & Divide Equations To solve a multiplication equation Use the inverse operation for multiplication which is division. Get the variable alone, by dividing the same number into both sides.

Try to solve this multiplication equation. Multiply & Divide Equations Try to solve this multiplication equation. How do you get x all by itself? = 8x -56

Multiply & Divide Equations Divide 8 into both sides. = 8x 56 -7 8 8

•-7 = 8x 56 Divide 8 into both sides. Multiply & Divide Equations Divide 8 into both sides. Check your answer by substitution! = 8x •-7 56

Try to solve this multiplication equation Multiply & Divide Equations Try to solve this multiplication equation How do you get x all by itself? = 42 -7x

Multiply & Divide Equations Divide 7 into both sides. = 42 -7x -6 -7 -7

•-6 Divide 7 into both sides. = 42 -7x Multiply & Divide Equations Divide 7 into both sides. Check your answer by substitution! = 42 -7x •-6

To Solve a Multiplication Equation Multiply & Divide Equations Divide the same number into both sides To Solve a Multiplication Equation 8x = 32 Get the variable alone. 8 8 Divide 8 into both sides. x = 4 8 divided by 8 cancels out 8 • 4 = 32 Show your check! 32 = 32 Finish your check!

Multiply & Divide Equations 1) 3) 2) 4)

To solve a division equation Multiply & Divide Equations To solve a division equation Use the inverse operation for division which is multiplication. Get the variable alone, by multiplying the same number to both sides.

Try to solve this division equation Multiply & Divide Equations Try to solve this division equation How do you get x all by itself? x 3 = 15

Multiply & Divide Equations Multiply both sides by 3 x 3 = •3 45 •3 15

45 x = 3 15 Multiply both sides by 3 Multiply & Divide Equations Multiply both sides by 3 Check your answer by substitution! 45 x 3 = 15

Try to solve this division equation Multiply & Divide Equations Try to solve this division equation How do you get x all by itself? x 6 = 4

Multiply & Divide Equations Multiply both sides by 6 x 6 = •6 24 4 •6

24 x = 6 4 Multiply both sides by 6 Check your answer by substitution! Multiply & Divide Equations Multiply both sides by 6 Check your answer by substitution! 24 x 6 = 4

Try to solve this division equation Multiply & Divide Equations Try to solve this division equation How do you get x all by itself? x 7 = -7

Multiply & Divide Equations Multiply both sides by 7 x 7 = •7 -49 -7 •7

-49 x = 7 -7 Multiply both sides by 7 Multiply & Divide Equations Multiply both sides by 7 Check your answer by substitution! -49 x 7 = -7

To Solve a Division Equation Multiply & Divide Equations To Solve a Division Equation Multiply the same number to both sides. x 3 = 25 Get the variable alone. 3• •3 = 25 x 3 Multiply both sides by 3. 3 divided by 3 cancels out to 1. x = 75 Show your check! Finish your check! 25 = 25

Try These Equations Show your check! Multiply & Divide Equations Try These Equations Show your check! -3x = 21 m = 8 -2 (-2) -3 -3 m = -16 x = -7 -3(-7) = 21 21 = 21 8 = 8

Multiply & Divide Equations Try These Equations 1) 2)

Multiply & Divide Equations Try These Equations 3) 4)