Could you help me

You have to use Y Editor to define functions on the both sides of the equation and then graph it. Finally option is F5: Intersection.
See captured images for equation 5x+10=-2x-7, y1=5x+10, y2=-2x-7 and x=-17/7

After you enter the data draw the SCATTER plot first.
When you perform the (linear) regression analysis LineReg, save the regression equation to a function, for example Y1
The syntax is
LineReg L1, L2, Y1 ENTER


From the Stat>CALC menu press LineReg
The command echoes on command line
Press [2nd][1] to enter the L1 list on command line
Press [,] to separate
Press [2nd] [2] to enter L2 on the command line
Press [,] the comma again
Press [VARS][>][Y-Vars][1~Function][1:Y1] [ENTER]
Press [GRAPH] to have the regression line equation drawn
on the same screen as the Scatter Plot you drew before.

See image below

If I'm understanding you correctly, you want to graph something like

5x+3=9

If this is correct, graph 5x+3 in the y1 line and 9 in the y2 line. To find the solution, you will press 2nd, then trace the intersection and hit enter 3 times. This will get the solution you need for the equation.

If this is not what you are wanting to do, you need to be try again and elaborate more.

1. You draw two or more graphs.
2. After the graphs are displayed, press [2nd][TRACE] to access the (CALC)ulate menu.
   
3. Select [5:Interesct]
4. You will be prompted for a first curve: the equation of the curve will be displayed at the top left corner of the screen. If it is one the intersecting curves, press [ENTER]
5. You will be prompted for the second curve. (You can move from one curve to another by pressing the UpArrow or DownArrow).
6. After two curves are selected, you will be prompted for a guess for the X-value of an intersection point: you can use the keypad to enter a guess or use the left or right arrow to move the cursor towards a point of your choosing (if there are more than one point).
7. After a short while the calculator gives you a solution.
8. If it fails, you must make a better guess.
   

Hello,
The function Intersect from the CALCULATE menu finf the coordinates of a point at which two or more curves intersect.
To use it:
1. Draw the functions.

2. Press [2nd][CALC][5:Intersect]



The cursor is on one of the curves. Read the equation top of the screen. If it is one of the curves you want press [ENTER]. The cursor jumps to another curve (in this case the only other curve).

Read the equation on top of the screen to verify thst it is the correct one. Press [ENTER]. The calculator asks asks for a guess of the coordinates of the intersection point.


As the intersection point is to the left of the current cursor position, use the left arrow to move cursor closer to the point.


Press [ENTER], and wait for the solution. Here it is.


In your question you talk about y intercept. If you want to calculate the ordinate of the point where a curve intersects the Y-axis, it is more efficient to use the [2nd][CAL][1:Value] selection.

You enter X=0 and press [ENTER]. The cursor jumps on the first curve (Y1=) an gives you the y-intercept.

Notice the position of cursor on graph. The y-value at the bottom is its ordinate.
To get the y-intercept of the second curve, leave the cursor on y axis and press the DownArrow. Cursor jumps to tthe second curve.
Since the X=0 is still stored, the value of y is displayed directly.



Hope it helps.

i think there are programs but with something as simple as that you should be able to work it out manually....
3x+25-5x=5x-5x
-2x+25-25=0-25
-2x=-25
x=25/2 or 12.5

The calculator only displays from -10 to 10 on the x and y axes, and both of your lines are outside of that range. However, it is easy to change that.

1. Hit the gray "WINDOW" button that is directly under the screen
2. Change "Xmax" to 150
3. Change "Ymax" to 200

Remember to change both of those values back to 10 when you are done with this problem!

Here's how to graph it:
1. Hit the "Y=" button
2. Enter your first equation after Y1, and your second equation after Y2
3. Look over both the equations to make sure you typed them correctly
4. Hit the "GRAPH" button
5. If you don't see the intersection you will need to adjust Xmax and Ymax again
6. Hit Hit "2ND" and the "TRACE" to bring up the "CALC" menu
7. Scroll down to "intersect" and hit enter
8. Hit enter 3 times (You use the first and second curve options when you have more than 2 lines)
9. It should display the coordinates at the bottom
10. I got (76, 142.1) for the intersection

Thanks for asking this question! I used to do this a much harder way, but while I was calculating the answer to your question I hit a wrong button and accidentally found this method!

go to apps menu, go to transform app. click uninstall and go to y= screnn and should be a slash on the left and you should be able to graph more than one equation.

This is my first post on this site, but I've had friends at school ask me about this. Apparently I'm like a calculator genius or something...

One solution I know of is clearing the RAM. Sounds strange, doesn't it? But it fixed three different calcs.

Be sure to back up or archive important data before doing this.