SOLUTION: My Dad has helped me and we still can't get this last few question, please help me. I dont understand all the question. I want to get all right, not just pass 1) 5x-4y=-18 I wou

Algebra ->  Linear-equations -> SOLUTION: My Dad has helped me and we still can't get this last few question, please help me. I dont understand all the question. I want to get all right, not just pass 1) 5x-4y=-18 I wou      Log On


   



Question 325419: My Dad has helped me and we still can't get this last few question, please help me. I dont understand all the question. I want to get all right, not just pass
1) 5x-4y=-18 I would like to know to solve not just answer
2) -x-2y=-10 I think got 2 (-2,-4) (-1,-5)
3) -y=x+1 I just don't get this
4) 2y=3x+11 again I just not get it,

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Notice that all of the given equations have two variables (x and y).
You can't "solve" these equations unless you place some constraints on the variables, such as..."x and y must be integers"
The given equations will have many answers, not just one.
Here's one way to think about these:
Suppose we were to graph the first equation: 5x-4y+=+-18by first solving it in terms of y.
5x-4y+=+-18 Subtract 5x from both sides.
-4y+=+-5x-18 Now divide both sides by -4.
y+=+%285%2F4%29x%2B9%2F2 Now we'll graph this:
graph%28400%2C400%2C-5%2C5%2C-5%2C6%2C%285%2F4%29x%2B9%2F2%29
You can immediately see that the value of y depends upon which value of x you choose, so you see that there are numerous solutions to such an equation, one for every value of x you choose.
Sometimes, when you are asked to solve equations with two variables, what is really meant is to put the given equation in terms of one of the variables as we did here:
y+=+%285%2F4%29x%2B9%2F2
Sometimes you are asked to find the x- and y-intercepts of equations like this.
You can do this by either inspecting the graph to see at which points the line intersects the axes. In this case, the x-intercept is x+=+-18%2F5 and the y-intercept is y+=+9%2F2 or by using algebra.