Solving Equations by by Solving Equations 1 3
Solving Equations by by Solving Equations 1 -3 Multiplying or Dividing Warm Up Lesson Presentation Lesson Quiz Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Objective Solve one-step equations in one variable by using multiplication or division. Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Solving an equation that contains multiplication or division is similar to solving an equation that contains addition or subtraction. Use inverse operations to undo the operations on the variable. Inverse Operations Operation Multiplication Division Holt Mc. Dougal Algebra 1 Inverse Operation Division Multiplication
Solving Equations by 1 -3 Multiplying or Dividing Example 1 A: Solving Equations by Using Multiplication Solve the equation. j – 8 = 3 Since j is divided by 3, multiply both sides by 3 to undo the division. – 24 = j Check j – 8 = 3 – 8 – 24 3 – 8 Holt Mc. Dougal Algebra 1 To check your solution, substitute – 24 for j in the original equation.
Solving Equations by 1 -3 Multiplying or Dividing Example 1 B: Solving Equations by Using Multiplication Solve the equation. n = 2. 8 6 Since n is divided by 6, multiply both sides by 6 to undo the division. n = 16. 8 n = 2. 8 Check 6 To check your solution, 16. 8 2. 8 substitute 16. 8 for n in the 6 2. 8 original equation. Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Example 2 A: Solving Equations by Using Division Solve the equation. Check your answer. 9 y = 108 y = 12 Check Since y is multiplied by 9, divide both sides by 9 to undo the multiplication. 9 y = 108 9(12) 108 To check your solution, substitute 12 for y in the 108 original equation. Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Example 2 B: Solving Equations by Using Division Solve the equation. Check your answer. – 4. 8 = – 6 v 0. 8 = v Since v is multiplied by – 6, divide both sides by – 6 to undo the multiplication. Check – 4. 8 = – 6 v – 4. 8 – 6(0. 8) – 4. 8 Holt Mc. Dougal Algebra 1 To check your solution, substitute 0. 8 for v in the original equation.
Solving Equations by 1 -3 Multiplying or Dividing Check It Out! Example 2 b Solve the equation. Check your answer. 0. 5 y = – 10 y = – 20 Since y is multiplied by 0. 5, divide both sides by 0. 5 to undo the multiplication. Check 0. 5 y = – 10 To check your solution, 0. 5(– 20) – 10 substitute – 20 for y in the original equation. Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Example 3 A: Solving Equations That Contain Fractions Solve the equation. 5 w = 20 6 The reciprocal of 5 is 6. Since w is 6 5 5 multiplied by , multiply both sides 6 6 by. 5 w = 24 Check 5 w = 20 6 20 20 20 Holt Mc. Dougal Algebra 1 To check your solution, substitute 24 for w in the original equation.
Solving Equations by 1 -3 Multiplying or Dividing Example 3 B: Solving Equations That Contain Fractions Solve the equation. 3 = 1 z 16 8 The reciprocal of 1 is 8. Since z is 8 1 multiplied by , multiply both sides 8 by 8. 3=z 2 3 =1 z Check 16 8 To check your solution, substitute 3 for z in the 2 original equation. 3 3 16 16 Holt Mc. Dougal Algebra 1
Solving Equations by 1 -3 Multiplying or Dividing Check It Out! Example 3 a Solve the equation. Check your answer. 1 – 1 = b 5 4 5=b – 4 Check The reciprocal of 1 is 5. Since b is 5 1 multiplied by , multiply both sides 5 by 5. 1 1 = b – 4 5 Holt Mc. Dougal Algebra 1 To check your solution, substitute – 5 for b in the 4 original equation.
Solving Equations by 1 -3 Multiplying or Dividing Check It Out! Example 3 c Solve the equation. 1 w = 102 6 The reciprocal of 1 is 6. Since w is 6 multiplied by 1 , multiply both sides 6 by 6. w = 712 Check 1 w = 102 6 102 102 Holt Mc. Dougal Algebra 1 To check your solution, substitute 712 for w in the original equation.
Solving Equations by 1 -3 Multiplying or Dividing Lesson Quiz: Part 2 9 7. A person's weight on Venus is about his or 10 her weight on Earth. Write and solve an equation to find how much a person weighs on Earth if he or she weighs 108 pounds on Venus. Holt Mc. Dougal Algebra 1
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