Sovling a system by addition method

[judyb]

Hi There,
My name is Rochelle, and I am failing Begining Algebra . The problem is solving a system by addition method.

5x - 2y = 9
-5x + 3y = -11.

I think the x's cancel out, and I added 2y, and 3y and got 5y. Then added the 9, and -11 and got 2. It gets hazy from there. Please show me how this is worked out.


Thank you,
Rochelle

 

[galactus]

-2 +3 does not equal 5. It equals 1.

You just add the same way you add anything else.

You're correct 5+(-5)=0, therefore, the x's are cancelled out.

5x-2y=9
-5x+3y=-11
---------------
0x+1y=-2

y=-2

Sub y=-2 into the first equation to get 5x-2(-2)=9-->5x+4=9--->5x=5.

x=1

See?. Easy.