SOLUTION: how would I understand the the linear systems of by substutition. I am so confused bout that.The most confusing questions for me are for example:y=x-4 3x+2y=7

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: how would I understand the the linear systems of by substutition. I am so confused bout that.The most confusing questions for me are for example:y=x-4 3x+2y=7       Log On


   

Question 268057: how would I understand the the linear systems of by substutition. I am so confused bout that.The most confusing questions for me are for example:y=x-4 3x+2y=7
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Here's the basic idea:

Step 1) Pick an equation and a variable to solve for. In this case, we're given y=x-4 which is already solved for 'y' (ie 'y' is isolated on one side). So we don't have to do this step.


Step 2) Move onto the other equation and plug in y=x-4. In other words, replace each 'y' term with 'x-4'. Doing this gets you 3x%2B2%28x-4%29=7. From here, we have a simple linear equation.

Step 3) Since you have a simple linear equation with one variable, you can easily solve for that variable (if a solution exists).

Step 4) Once you have a solution in terms of 'x', plug that value into y=x-4 to find the solution in terms of 'y'.