|
Question 273014: Can someone explain the steps to solve for y for graphing for linear equations? I am having trouble with the equation y = -1/2x -4. I can solve for y without any problem with the variables given for x, but for some reason I am not understanding how to solve for x when given the variable for y. For example, I know that y is -1 and that the answer is -6, but I cannot seem to get the correct answer on my own.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Can someone explain the steps to solve for y for graphing for linear equations? I am having trouble with the equation y = -1/2x -4.
------
It is a linear equation. You need two points to obtain a graph.
---
Let x = 0, then y = (-1/2)*0-4, y = -4 giving you point (0,-4)
-----------------
Let x = 2, then y = (-1/2)*2-4, y = -1-4 = -5 giving you point (2,-5)
-------
Plot those two points and draw a line thru them to get:
---------------
I can solve for y without any problem with the variables given for x, but for some reason I am not understanding how to solve for x when given the variable for y. For example, I know that y is -1 and that the answer is -6, but I cannot seem to get the correct answer on my own.
y = (-1/2)x-4
Solve for "x":
2y = -x - 8
x = -2y-8
If you let y = -1, x= -2*-1-8 = 2-8 = -6
If you let y = 5, x = -2*5-8 = -18
---
Cheers,
Stan H.
|
|
|
| |
