To solve this, first..
make a table for the values of x and y for both the equations..
like this-
x 1  2  3
y -1 -2 -3.... for first equation..
Then we plot the points on the graph to obtain the graphical representation of the first equation.
We do the same with the second equation and make its graph.
Remember.. make bothvthe graphs of the equation on the same graph paper.
Wherever the two lines formed meet..
that is the answer!

Hope this helped! :P :)