Question 268057
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+2(x-4)=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'.