##### solving system of equations by graphing

label Mathematics
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I'm struggling with graphing two equations ... for example 3x + 2y =8 and x -4y =-12

how do i know what number to use for x?

May 26th, 2015

3x + 2y=8

here

y=(8-3x)/2

y=5/2=2.5

for x=2

y=1

for x=3

y=-1/2= -0.5

and so on for more values of x
scale x axis with 0,1,2,3....
and scale y axis with -1,-2-3,0,1,2,3......

and point on graph according to the value of x and y for example for x =2,   y=1 make a dot at (2,1) at the graph and do this procedure for more values of x then joint them all with straight line from one point to other

do this procedure for the other equation as well with same values of x......

May 26th, 2015

I'm sorry....I'm still confused... if y=5/2x - 8 then for the y = mx + b, do I plot the 8 on my graph then for the m=rise/run, i plot up the y axis 5 points and go right (the run) 2 points, up 5 over 2 up 5 over 2, etc...then connect the points??

May 26th, 2015

because there is a - in front of the 8, i would go down the y-axis?

May 26th, 2015

y = mx + b dear this is point slop equation
no need to consider it in your mind

just use x values from 1 to so on and find corresponding values of y from the given equation
and simply plot them

May 26th, 2015

i got the intersecting point as (4, 2)

May 26th, 2015

dear it should be  (4, -2)

May 26th, 2015

i m truly not grasping the negative....i got my graph completely inverted from what you got ...what do i do when they give an answer for y? for example; y=2x, and y= -x - 3?? :-(

May 26th, 2015

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May 26th, 2015
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May 26th, 2015
Oct 19th, 2017
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