Question 1190677
2x+y=-4
x+y=-7
Find the first variable and isolate it. Then solve for that variable.
solve for the second variable 
find the numerical value of the first variable.
(when I say the first variable it's any variable that you would want to start with...that's what my teacher said)
I don't really understand how to do this so could somebody please explain 
<pre>That person's WRONG!!  {{{system(x <> - 11, and, y <> 18)}}}
2x + y = - 4 ----- eq (i)
x + y = - 7____x = - 7 - y ---- eq (ii)
2(- 7 - y) + y = - 4 ----- Substituting - 7 - y for x in eq (i)
- 14 - 2y + y = - 4
- y = 10
{{{highlight_green(matrix(1,5, y, "=", 10/(- 1), "=", - 10))}}}
x = - 7 - (- 10) ------- Substituting - 10 for y in eq (ii)
{{{highlight_green(matrix(1,5, x, "=", - 7 + 10, "=", 3))}}}