SOLUTION: solve the equation graghically 3x+4=x-6 thank you for helping me.

Algebra ->  Linear-equations -> SOLUTION: solve the equation graghically 3x+4=x-6 thank you for helping me.      Log On


   

Question 152426: solve the equation graghically
3x+4=x-6
thank you for helping me.
Found 2 solutions by jim_thompson5910, Edwin McCravy:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First graph the left side as its own equation y=3x%2B4

Graph of y=3x%2B4

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


Now graph the right side as its own equation y=x-6

Graph of y=x-6


Graphing the two together, we get

Graph of y=3x%2B4 (red) y=x-6 (green)


From the graph, we can see that the two lines intersect at the point (-5,-11) where x=-5 and y=-11. So the solution to the equation 3x%2B4=x-6 is x=-5

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!

solve the equation graghically 
3x+4=x-6 
thank you for helping me.


Let y = the left side

    y = 3x+4

Let y = the right side

    y = x-6

So this gives us two equations to graph.

So we graph them:

graph%28400%2C400%2C-10%2C10%2C-14%2C6%2C3x%2B4%2Cx-6%29 

Now to find the value of x, we draw a line
straight up to the x-axis, and see where it
hits the x-axis:



It hits the x-axis at x=-5. So that's the answer.

To do it on a TI-83 or TI-84

Press Y=
After \Y1=  type 3X+4
After \Y2=  type X-6
Press Zoom
Press 0   (See graph)
Press 2nd TRACE
Press 5
Press ENTER 
Press ENTER
Press ENTER

See at bottom of graph:

Intersection
X=-5                Y=-11

So the answer is x=-5

Edwin