1 / 15

Solving Equations (Multiplication & Division)

Solving Equations (Multiplication & Division). Grade Seven & Eight Mathematics M. M. Couturier. Solving Algebraic Expressions. Recall that when solving problems of this nature: x + 6 = 36; when isolate the x by eliminating what is next to it;

ikes
Télécharger la présentation

Solving Equations (Multiplication & Division)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Solving Equations (Multiplication & Division) Grade Seven & Eight Mathematics M. M. Couturier

  2. Solving Algebraic Expressions • Recall that when solving problems of this nature: • x + 6 = 36; when isolate the x by eliminating what is next to it; • x + 6 – 6 = 36 – 6 ; we eliminate +6 by subtracting 6 (the opposite of the operation). • x = 30

  3. Solving Algebraic Expressions • Likewise, if the problem were, • x - 6 = 36; we would still isolate the x but this time we add 6 (the opposite of –6) • x - 6 + 6 = 36 + 6 ; which yields; • x = 42

  4. Solving Algebraic Expressions • When faced with a multiplication problem, we will use a similar strategy; • Example: • 3x = 15 • First we want to isolate x; but to do so we must eliminate the multiple of 3. To do so, we will have to divide both sides by 3.

  5. Solving Algebraic Expressions • This means we will have: • 3x = 15 • 3 3 • Since 3/3 = 1, the x is isolated; • x = 5; • Don’t forget to do your check.

  6. Solving Algebraic Expressions • Example # 2: Solve for f, if 6f = 66 • First we will want to isolate for f, so we are going to have to divide both sides by 6. • 6f = 66 • 6 6 • Since 6/6 = 1, f is isolated; • f = 11; • Don’t forget to do your check.

  7. Solving Algebraic Expressions • Example # 3: Solve for g, if 9g = 54 • Try this one on your own!

  8. Solving Algebraic Expressions • Solution to Example # 3: Solve for g, if 9g = 54 • First step: isolate for g; by dividing both sides by 9. • 9g = 54 • 9 9 • Since 9/9 = 1, g is isolated; • g = 6; • Did you do your check?

  9. Solving Algebraic Expressions • What about division problems? Well, what is the opposite of division; multiplication! So when faced with a division problem, you will isolate the variable in question by multiplying both sides by its denominator.

  10. Solving Algebraic Expressions • Example: Solve for h; h = 10 • 2 • Our first step is to isolate the h, so to do that we must eliminate the ½. To do that, we will multiply both sides by 2. • (2)h = 10(2) • 2

  11. Solving Algebraic Expressions • Since 2/2 = 1; • h = 20 • Don’t forget to check your answer.

  12. Solving Algebraic Expressions • Example: Solve for p, if p = 7 • 3 • Isolate p by multiplying 3 on both sides. • p = 7; • 3 • (3)p = 7(3) • 3 • Since 3/3 = 1; • p = 21 • Don’t forget to check your answer.

  13. Solving Algebraic Expressions • Example: Solve for k, if k = 12 • 5 • Try this one on your own!

  14. Solving Algebraic Expressions • Example: Solve for k, if k = 12 • 5 • Isolate k by multiplying 5 on both sides. • k = 12; • 5 • (5)k = 12(5) • 5 • Since 5/5 = 1; • p = 60 • Did you check your answer?

  15. Solving Algebraic Expressions • Take extra careful note: • (6)(6) = 36 • (-6)(6) = -36 • (6)(–6) = -36 • (-6)(-6) = 36

More Related