algebra
posted by lila on .
hi
could you please take me through the steps of solving the simultaneous equation graphically thank you.
yx+4=0
y8+x=0

By solving it graphically, I presume the question means draw the graph, and read off the answer from the point where the lines cross.
To do that, you need to draw each of the two lines.
Start with the first one: yx+4=0. You need to find two points on that line, then use your ruler to draw the straight line that joins them. Any ttwo points will do, but the intercepts, where x=0 and where y=0 are usually good.
So, when x=0, we have y0+4=0, or y=4, so one point is (0, 4)
When y=0, we have 0x+4=0, or x=4, so the point (4,0) is on this line.
Draw the line passing through (0,4) and (4,0).
Now do the same for the other line.
The two lines cross at your answer, and you can read off both x and y. (Check: You should see that x=6 at your answer)