1. Slideshow 13, Mathematics Mr Richard Sasaki, Room 307

2. Look at multiplying both sides of an equation by a number Review the process of solving simultaneous equations Solve simultaneous equations for unknowns with different coefficients

3. Try the short multiplication worksheet and fill in the gaps, should take just a few minutes!

4. 4 5 3 9 11 8 -4 2 3 -2

5. We can solve simultaneous equations by adding or subtracting when a term and coefficient is the same in both equations. ① ② ①－②①－② ①

6. But how do we solve simultaneous equations when there is no term and coefficient in common? As in the multiplication worksheet, we can multiply both sides of an equation by a number. We can make it so the same term shares the same coefficient.

7. Example Solve the simultaneous equations below. ① ② ②×2 So let’s subtract ① from ②×2. ① ②×2 ②

8. Example Solve the simultaneous equations below. ① ② ① x 3 ② x 2 ① x 3 - ② x 2 ① Try the worksheets!

10. Chicken eggs: 20g Duck eggs: 35g There are 15 two yen coins and 25 five yen coins