Welcome to Fall 2011 semester Math 7A class!

Today we had a quick skill review test to go over some concepts taught in Math 6. This serves two purposes: for me, it is to know the level each student comes with; for student, it is for him/her to know whether he/she is ready and what he/she is missing.

We went over the review and talked more about one variable linear equation, its graph, and one variable linear inequality.

We then went over the content in 7.1 and 7.2 on solving 2-variable linear system (2 2-variable linear equations) by graphing and substitution.

For solving the system by graphing, you first graph the first equation, then graph the 2nd equation in the same coordinate system. The intersection is your solution, so you estimate the interception. Last step is to take the estimated solution and plug it back into the original equations to make sure that they both work.

For solving the system by substituion, you first take  one equeation and rewrite it so that one variable is represted by the other. Then you substitute this variable in the other equeation with the represenation you got from the first step. Now you have an one-variable linear equation. Solve it, then solve the other variable. Again, the last step is to take the solution and plug in back into the origianl equations to make sure that they both work. This step will help you identify potential errors.

For the homework, please download the following pdf file and print it out. Homework is due next Sunday.

http://blog.newtonchineseschool.org/wangweidong/files/2011/09/Math7_Fall_HW_L1.pdf