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Solving Simple Simultaneous Equations. Slideshow 12, Mr Richard Sasaki Mathematics, Room 307. Objectives. Review how to subtract polynomials in vertical form Look at how simultaneous equations work Solve simultaneous equations with one coefficient and term the same.
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Solving Simple Simultaneous Equations Slideshow 12, Mr Richard Sasaki Mathematics, Room 307
Objectives • Review how to subtract polynomials in vertical form • Look at how simultaneous equations work • Solve simultaneous equations with one coefficient and term the same.
Subtracting Polynomials - Review Subtracting Polynomials can be done vertically, in the same way as subtracting two numbers. We can calculate from left to right or right to left. Try the worksheet! Examples 19x + 8y -
Simultaneous Equations Linear simultaneous equations with two unknowns usually have two only one possibility for each unknown. Each unknown only represents one number. You may have realised this from last lesson. Simultaneous means “at the same time”. These two (or more) equations work together at the same time. So how do we solve them?
Simultaneous Equations Today, we will look at examples where a coefficient and term are the same in each equation. Example Solve the simultaneous equations below. What can we do to solve for x or y? ① ② Yes, let’s subtract the top from the bottom! Then we can remove x and solve for y. ①-② ① Now we need to substitute y = 1 into ① or ②. Either are okay! So and .
Simultaneous Equations Let’s try another example. Example Solve the simultaneous equations below. ① Yes, let’s subtract the top from the bottom again. (Subtracting the bottom from the top is also okay). Once again, we can remove and solve for . ② ①-② ① Substitute = __ into whichever looks easiest. So and .
Simultaneous Equations So for a summary, to solve simultaneous equations like this, we subtract one from another (doesn’t matter which) and solve for the other unknown. Then we substitute this into one of the equations (whichever you like) and find the result for the other. Remember to write your answer clearly at the end! Good luck and try the worksheets!
Answers – Easy & Medium -3 3 5 1 8 2 It disappears. 2 0 It disappears. 4 -9 7 2 3 3 2 9
Answers – Hard 1 2 3 5 3 5 3 3 5 4 2 5