7.3

7.3 examples.

**Main idea: Solve Linear Systems by Adding or Subtracting.** **Max Rainsford** 1.) 2x+3y=11 -2x+5y=13 8y=24 y=3 2x+3(3)=11 -2x+5(3)=13 x=1 2.) 4x+3y=2 5x+3y=-2

SOLVE #2 FOR YOURSELF //Jafaar Sule// 1) 4x-3y=5 -2x __-2x+3y=-7__ 2x =-2 x=-1 __**Taylor Mihaljevic**__ __**Main Idea:**__

When coefficients of one variable are the same you should subtract, otherwise add. __**Solved Problem**__
 * 4x-3y=5**
 * -2x+3y= -7**

solution: you should add the two equations to start out with. then you will end up with the problem: 2x= -2 ___ divide 2 2 so that x=1
 * then plug 1 into every "x" in your problem.

(4x1)+ -3y=5 -4+-3y=5 -5y=5 _ divide -5 -5


 * to get y=1
 * your final answer will be y=1 and x=1

__**Unsolved Problem**__ -5x-6y=8 5x+2y=4

Adam Sclafani

Main idea- add or subtract to eliminate variable, solve the equation for the other variable, substitute in one original equation to find the variable

1) 2x+3y=11 +-2x+5y=13 8y=24 y=3

2x+3y=11 2x+3x3=11 x=1

2) 4x+3y=2 - 5x+3Y=-2

=**MICHAEL LUXTON**= __**-2x+5y=13**__ //**y=3**//
 * Main Idea: Add or subtract the equations to eleminate __//one//__ variable**
 * Problem#1**
 * 2x+3y=11**
 * -2x+5y=13**
 * 2x+3y=11**
 * 8y=24**

**Problem#2**
__**5x+3y=-2**__ //**x=-4**//
 * 4x+3y=2**
 * -x =4**