Questions on Algebra: Systems of Linear Equations answered by real tutors!

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Question 169652: NEED HELP PLEASE!!!!
solve by graphing
x-2y=-8
3x+4y=6
: NEED HELP PLEASE!!!!
solve by graphing
x-2y=-8
3x+4y=6

Answer by jim_thompson5910(9921) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system of equations:


system(x-2y=-8,3x+4y=6)


In order to graph these equations, we must solve for y first.


Let's graph the first equation:


x-2y=-8 Start with the first equation.


-2y=-8-x Subtract x from both sides.


y=(-8-x)/(-2) Divide both sides by -2 to isolate y.


y=(1/2)x+4 Rearrange the terms and simplify.


Now let's graph the equation:


drawing(500,500,-10,10,-10,10,<BR>
grid(0),<BR>
graph(500,500,-10,10,-10,10,(1/2)x+4)<BR>
) Graph of y=(1/2)x+4.


-------------------------------------------------------------------


Now let's graph the second equation:


3x+4y=6 Start with the second equation.


4y=6-3x Subtract 3x from both sides.


y=(6-3x)/(4) Divide both sides by 4 to isolate y.


y=-(3/4)x+3/2 Rearrange the terms and simplify.


Now let's graph the equation:


drawing(500,500,-10,10,-10,10,<BR>
grid(0),<BR>
graph(500,500,-10,10,-10,10,-(3/4)x+3/2)<BR>
) Graph of y=-(3/4)x+3/2.


-------------------------------------------------------------------


Now let's graph the two equations together:


drawing(500,500,-10,10,-10,10,<BR>
grid(1),<BR>
graph(500,500,-10,10,-10,10,(1/2)x+4,-(3/4)x+3/2)<BR>
) Graph of y=(1/2)x+4 (red). Graph of y=-(3/4)x+3/2 (green)


From the graph, we can see that the two lines intersect at the point . So the solution to the system of equations is . This tells us that the system of equations is consistent and independent.