1. Equations Lesson 1 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths ©2007 M Timmons 1 Topics To be Covered The Idea of an Equation 31 May 2016

2. When we have discovered this number we have solved the equation The idea of an equation Think of the problem ?+4=7 This is called an equation Do you know what the number is? The answer is 3 231 May 2016 If we let x stand for the number What number is the ?

3. Try the following yourself Some Examples Find the missing numbers? 3 31 May 2016

4. Try Questions from Text Book Some Examples Find the missing numbers? 4 31 May 2016

5. The left hand side must balance with the right hand side Working with scales 531 May 2016 Find the weight of the if = 7 = 14 The mass (in grams) of one shape in the following diagram is given, find the mass of the other shape?

6. Try Questions from Text Book The mass (in grams) of one shape in the following diagram is given, find the mass of the other shape? 631 May 2016 Find the weight of the if = 10 = 15

7. Equations Lesson 2 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 7 Topics To be Covered Solving Equations 31 May 2016

8. Try the following yourself Some Examples Solve the equation 8 31 May 2016

9. Here x has different values that is why it is called a variable Some Examples Solve the equation 9 31 May 2016

10. When we have found what x is we have solved the equation. Rules for solving an equation 1. Get the x on the L.H.S. 4. If you multiply or divide the L.H.S. by a number you must multiply or divide the R.H.S by the same number 1031 May 2016 3. When a number or letter crosses the = it changes sign 2. Get everything else to the R.H.S.

11. Try the following two Examples Examples: Solve the equation 11 31 May 2016

12. Try Questions from Text Book Try the following: Solve the equation 12 31 May 2016

13. Equations Lesson 3 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 13 Topics To be Covered Solving Equations with letters on both sides 31 May 2016

14. Letters to the L.H.S. Numbers to the R.H.S. Examples: Solve the equation 14 31 May 2016

15. Letters to the L.H.S. Numbers to the R.H.S. They change sign when they cross the = Try the following yourself: Solve the equation 15 31 May 2016

16. Try Questions from Text Book Try the following yourself: Solve the equation 16 31 May 2016

17. Equations Lesson 4 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 17 Topics To be Covered Forming Equations 31 May 2016

18. When we have discovered the number we have solved the equation Forming equations I think of a number and add 2 to it, if the result is 11, find the number. The problem has been changed into an equation: You can now solve the equation? 1831 May 2016 If we let x stand for the number, we could write the problem as :

19. We have changed the problem into an equation, which we then solved Try the following I think of a number and take 3 from it, if the result is 21, find the number. The problem has seen changed into an equation: You can now solve the equation? 1931 May 2016 If we let x stand for the number, we could write the problem as

20. Try the following yourself Some Examples: Form the expression: 20 31 May 2016

21. Try Questions from Text Book Some Questions: Form the expression: 21 31 May 2016

22. Equations Lesson 5 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 22 Topics To be Covered Forming Equations (continued) 31 May 2016

23. Letters to the L.H.S. Numbers to the R.H.S. They change sign when they cross the = Write the following statements as algebraic equations and then solve: 23 31 May 2016

24. Here we divided both sides by 2. What ever number is in front of the x, Divide both sides by that number Try writing following statements as algebraic equations and then solving them yourself: 24 31 May 2016

25. Equations Lesson 6 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 25 Topics To be Covered Construct a statement based on an equation 31 May 2016

26. Here we have just carried out the reverse of forming an equation given a problem Construct a statement based on the equation: 2631 May 2016

27. Here we are constructing statements based on equations Try the following yourself Construct a statement based on the equation: 2731 May 2016

28. Equations Lesson 6 St. Joseph’s CBS Fairview Dublin 3 2.2 Maths 28 Topics To be Covered Solving Problems using Equations 31 May 2016

29. Remember, when we have discovered the number we have solved the equation Solving Problems using Equations Ex. 1 When 10 is added to three times a certain number, the result is 46. Find the number The problem has been changed into an equation: You can now solve the equation? 2931 May 2016 If we let x stand for the number, we could write the problem as :

30. Letters to the L.H.S., Numbers to the R.H.S., when they cross the = they must change sign Solving Problems using Equations Ex. 2 When 5 is taken from 6 times a certain number, the result is 31. Find the number The problem has been changed into an equation: You can now solve the equation? 3031 May 2016 If we let x stand for the number, we could write the problem as :

31. Solving equations, is an important part of Junior Certificate Mathematics Solving Problems using Equations Ex. 3 When 2 is taken from 5 times a certain number, the result is 28. Find the number The problem has been changed into an equation: You can now solve the equation? 3131 May 2016 If we let x stand for the number, we could write the problem as