Solve by graphing?

Question

Can I please get some help! I would appreciate it. here are the equations 3x -y = 1, 3x -y = 2. Next equation x-y = 2 3x-3y = 6

Answer 1

Graph both equations, you need to get it in slope-int form y=mx+b
3x -y = 1
-y = -3x + 1
y = 3x - 1

3x -y = 2
-y = -3x + 2
y = 3x - 2

Now look where they cross, these two will not cross because they are parallel lines ( same slope) So no solution.

x-y = 2
-y= -x +2
y= x -2

3x-3y = 6
-3y = -3x +6
y = x - 2

These two are the same line, so infinite solutions.

Answer 2

I'm not quite sure I understand the question, but if you want to solve by graphing, then solve the equation for y.

For example, 3x-y = 1. You first subtract 3x from both sides, that gives you -y = -3x +1. Then you multiply by -1 to get rid of the negitive. That leaves you with y = 3x -1.

Now, for graphing. First, -1 is your y-intercept. So on (0, -1) you put your point. 3 is your slope. So, from the point (0, -1) you use your slope to get the next point. 3 is 3/1 (3 over 1) so you go from your first point, to over 1, up three.

Your next point should wind up on (1, 2)

Answer 3

To solve by graphing, make a table of values or get y by itself and use slope/intercept. Graph both lines and see where they cross. If they cross at one point, that's the answer. If they turn out to be parallel, then there is no answer (which will happen in #1). If however they turn out to be the exact same line then there are infinitely many answers (any point on the line- this will happen in #2)

Answer 4

hay its a very simple qn
as we have 3x-y=1 we can convert it as y=3x-1

now take some values of x and get values of y
eg: x=1;y=2 x=2;y=5 x=-2;y=-7

Do the same for rest of the equation one by one then plot all the values on graph .
the common point of intersection of all the four graphs will be ur answer.
i hope u got it.
have a nice time!
bikash Jain

Answer 5

Draw the lines by hand. See whether and where they cross.

Actually, in the first case the lines are parallel; there is no solution. (If there were, 1=2, which can't happen.)

And in the second case, they're the same line, so everything that solves one is a joint solution.

Probably you understand what's going on perfectly well, but just got worried about the trick questions. Don't worry! ;)