Question 24635
I'm assuming that you probably meant to write:
y = x+7
y = -4x + 2


To solve by graphing, just draw the graphs and see where the two lines cross. If you need additional help obtaining the graphs of these lines, I wrote three lesson plans for algebra.com on graphing a straight line.  These are both in slope intercept form so graphing the lines should be easy.  


The first line has a y intercept of 7 and a slope of {{{(rise)/(run) = 1/1}}}.
The second line has a y intercept of 2, and a slope of {{{(rise)/run) = (-4)/1}}}.  They should look like this, 

{{{graph(400,400, -10,10,-10,10, x+7 , -4x +2)}}}


Notice that the lines cross at a point where x = -1, and y =6.  Therefore, the solution is the point (-1,6).


R^2 at SCC