SOLUTION: help... im doing an algebra course and i find myself totally lost..this is an example in my text. 2x + y =4 x - 3y =-5 the solution given is (1,2) using the graphing method s

Algebra ->  Rational-functions -> SOLUTION: help... im doing an algebra course and i find myself totally lost..this is an example in my text. 2x + y =4 x - 3y =-5 the solution given is (1,2) using the graphing method s      Log On


   

Question 704533: help... im doing an algebra course and i find myself totally lost..this is an example in my text.
2x + y =4
x - 3y =-5
the solution given is (1,2)
using the graphing method
step 1 says on a single set of coordinate axes, graph each equation.
and that right there is my problem.. i dont know how to graph them..a detailed working and explanation that i can use fr future reference will be highly appreciated.. thank you
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'll show you how to graph 2x+y = 4

First solve for y

2x+y = 4

y = 4 - 2x

y = -2x + 4

Looking at y=-2x%2B4 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=-2 and the y-intercept is b=4


Since b=4 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is -2, this means:

rise%2Frun=-2%2F1


which shows us that the rise is -2 and the run is 1. This means that to go from point to point, we can go down 2 and over 1



So starting at , go down 2 units


and to the right 1 unit to get to the next point



Now draw a line through these points to graph y=-2x%2B4

So this is the graph of y=-2x%2B4 through the points and


You follow the sames steps to graph x - 3y = -5