solving systems of equations using the elimination meathod  TOPIC_SOLVED

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.

solving systems of equations using the elimination meathod

Postby deltadawn on Thu Jan 08, 2009 10:11 pm

I have been really struggling here.


equations are: 8X-9y=24.5
7y -2x=-8.5 first change this to the other order -2x+7y=-8.5
then eliminate a variable?
deltadawn
 
Posts: 1
Joined: Thu Jan 08, 2009 10:06 pm

Sponsor

Sponsor
 

  TOPIC_SOLVED

Postby stapel_eliz on Fri Jan 09, 2009 12:06 am

deltadawn wrote:equations are: 8X-9y=24.5 and 7y -2x=-8.5
first change this to the other order -2x+7y=-8.5
then eliminate a variable?

I will guess that you mean "x" and "X" to actually be the same variable. (You can't solve the system otherwise.)

First, read this online lesson to learn the basic idea and methodology for solving a system of equations by "elimination". Then return here and continue....

You have the following:

. . . . .
. . . . .

Note that the -2(4) = -8, and that (8) + (-8) = 0. Then:

. . . . .
. . . . .

First, multiply out the second equation. Then what happens when you "add down"? :wink:

Eliz.
User avatar
stapel_eliz
 
Posts: 1781
Joined: Mon Dec 08, 2008 4:22 pm


Return to Beginning Algebra

cron