Instead of lecturing my students on solving systems of elimination (when both equations must be tinkered with), as I used to do, I now start class with a mini-lesson (15-20 minutes in length) to go over just the main idea of what they will be learning about today. I include two or three example problems to make sure they get the main idea:
I like to point out to kids that sometimes fraction problems such as 1/5 + 2/5 is straightforward (no manipulation required), whereas a problem such as 2/3 + 1/6 requires manipulation of one fraction, and problems such as 2/5 + 1/3 requires manipulation of both fractions.
Ex 1: 2x+5y= –4; –3x+4y = –17 (x =3, y = –2)
Ex 2: 2x – 5y = 52; 7x + 3y = 18 (x = 6, y = –8)
Ex 3: 3x + 2y = 10; 6x + 4y = 20 (TRUE: infinitely many solutions)
As soon as the mini-lesson is over, I set them to task on this worksheet. I use this activity within cooperative groups, and I circulate to make sure they are getting the purpose of the questions.
The file includes spiral review problems.
This worksheet is intended to be written on directly.
Please download the pdf preview file first, so you can see exactly what's included; the product file is a word document, which you may personalize for your students.
Immediately before this worksheet, I use the worksheet named 'Solving Systems by Elimination Part 1 Fall 2013' (http://www.teacherspayteachers.com/Product/Solving-Systems-by-Elimination-Part-1-Fall-2013-1125121
), and immediately after this worksheet, I use the assessment named 'Final Exam Accelerated Algebra 1 Fall 2013 Multiple Choice with Answer Key' (http://www.teacherspayteachers.com/Product/Final-Exam-Accelerated-Algebra-1-Fall-2013-Multiple-Choice-with-Answer-Key-1125212