1. Solving Mixed Equations Grade Seven & Eight Mathematics M. M. Couturier

2. Solving Equations In this class, we will combine the skills and techniques that we learned in the previous classes; how to solve for examples like: x + 6 = 10 and 3x = 15. However, this time we will combine addition/subtraction and multiplication/division situations.

3. Solving Equations Let’s look at a few examples; solve for x: 2x + 5 = 25 See if you can solve for this!

4. Solving Equations Let’s look at a few examples; solve for x: 2x + 5 = 25 Let’s isolate the variable by using reverse BEDMAS or SAMDEB; first we get rid of the +5. 2x + 5 - 5 = 25 - 5 2x = 20 Now we get rid of the multiple of 2. 2x = 20 2 2 x = 10; Therefore; x = 10.

5. Solving Equations Example # 2; solve for x in 6x - 14 = 46 Try this on your own for now!

6. Solving Equations Example # 2; solve for x in 6x - 14 = 46 Isolate the variable first getting rid of the -14. 6x - 14 + 14 = 46 + 14 6x = 60 Now get rid of the multiple of 6. 6x = 60 6 6 x = 10; Therefore; x = 10.

7. Solving Equations Example # 3; solve for x in; x - 8 = 10 2 Try this on your own!!!

8. Solving Equations Example # 3; solve for x in; x - 8 = 10 2 Isolate the variable by getting rid of the -8. x - 8 + 8 = 10 + 8 2 x = 18 2

9. Solving Equations Now we get rid of ½ by multiplying by 2. 2x = (2)18 2 x = 36 Therefore, x = 36.

10. Solving Equations Example # 4; solve for x in; 5x - 5 = 5 4 4 Try this one on your own!!!

11. Solving Equations Example # 4; solve for x in; 5x - 5 = 5 4 4 Now there is a secret that we can use. If you don’t like dealing with fractions, then multiply EVERYTHING by the largest denominator, which in this case is 4. (4)5x - (4)5 = (4)5 4 4

12. Solving Equations 5x - 5 = 20 Now we have a fractionless equation: 5x - 5 + 5 = 20 + 5 5x = 25 5 5 x = 5; Therefore, x = 5.

13. Solving Equations Try a few of these: A)4x + 15 = 35 B)-2x – 6 = -14 C)7x –1 = 20 D)5x – 50 = 20

14. Solving Equations Solution A) 4x + 15 = 35 4x + 15 – 15 = 35 – 15 4x = 20 4 4 x = 5; Therefore, x = 5.

15. Solving Equations Solution for B) -2x – 6 = -14 -2x – 6 + 6 = -14 + 6 -2x = -8 -2 -2 x = 4;Therefore, x = 4.

16. Solving Equations Solution for C) 7x –1 = 20 7x - 1+ 1 = 20 + 1 7x = 21 7 7 x = 3;Therefore, x = 3.

17. Solving Equations Solution for D) 5x – 50 = 20 5x – 50 + 50 = 20 + 50 5x = 70 5 5 x = 14;Therefore, x = 14.