SOLUTION: Please help! I have to solve by graphing 7x- 3y = 1 and 2y = 5x. I have no idea how to do it. Thanks so much

Algebra ->  Rational-functions -> SOLUTION: Please help! I have to solve by graphing 7x- 3y = 1 and 2y = 5x. I have no idea how to do it. Thanks so much      Log On


   



Question 505920: Please help! I have to solve by graphing 7x- 3y = 1 and 2y = 5x.
I have no idea how to do it.
Thanks so much

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
I have to solve by graphing 7x- 3y = 1 and 2y = 5x.
Put both equations into the slope/intercept format
7x - 3y = 1
-3y = -7x + 1
Y has to be positive, multiply both sides by -1
3y = 7x - 1
divide both sides by 3
y = 7%2F3x - 1%2F3; the slope/intercept form (Red)
and
2y = 5x
divide both sides y 2
y = 5%2F2x
y = 2.5x
:
Plot these equations from x=-3, to x=+1
y = 7%2F3x - 1%2F3
replace x with -3
y = 7%2F3(-3) - 1%2F3
y = -7 - 1%2F3
y = -71%2F3
y = - 7.33
do the same for x = -2, x = 0, and x = +1
--------------
x | y
--------
-3 |-7.333
-2 |-5
0 |-.333
+1 |+2
:
Do the same for y = 2.5x (green)
x | y
--------
-3 |-7.5
-2 |-5
0 | 0
+1 |2.5
:
You should note that where x=-2, y = -5 in both equation so this is the solution
-2,-5, this should be the intersection of the graph
:
Graph this with these points, intersection is not easy to see but should look like this
+graph%28+300%2C+200%2C+-4%2C+2%2C+-7%2C+4%2C+2.33x-.333%2C+2.5x%29+