i need help w/ math.?

Question

Solve each system by graphing. Check ur solution.
x+y=3
x-y=-1
How do i solve this?

Answer 1

You graph the lines and find the point of intersection by inspection (i.e. you look at it). You check it then by plugging the coordinates of the intersection into each equation and verifying that they work.

x + y = 3

y = -x + 3

This is a line with slope -1 passing through the point (0, 3).

x - y = -1

y = x + 1

This is a line with slope 1 passing through the point (0, 1)

Now graph them and go look.

Answer 2

x=2 y=1

Answer 3

First rearrange these equations into slope intercept form i.e.
y=mX+c (where m= slope of the line=Rise over Run ; c=where the line cuts the y axis)
y=-x+3 ----(1
y=x+1 ------(2
Now plot these line on a graph
To plot a line we need at least two points, right?
For (1) mark a point on y-axis where y=3 (cause c=3)
For other point first move 1 unit down and then 1 unit forward OR move 1 unit backward and then 1 unit up.(cause m=-1/1)
Hence you may reach the points (1,2) OR (-1,4)respectively.
Join any of these points with (0,3)to to get the line.

For the next line y intercept is 1 and slope is +1/+1.
Similarly. first point would be (0,1) on y-axis.And you can arrive at the next point by moving 1 unit up and then 1 unit forward, that point would be (1,2)
Join these two points to get the next line.

The point at which these two line intersects will be the solution for problem.That you can very well find out after plotting both the lines on the graph. From the point of intersection draw perpendicular to both the axis that will give you the poistion of that point and would be the solution for the problem.

Answer 4

x=2 y =1

2+1=3

2-1=1


that simple

Answer 5

Re-arrange the equations to y= form.

y= -x + 3
y= -x -1

Graph on a graphing calculator or on paper, and figure out the intersection of the two.
Double check by entering the x and y coordinates into the original equations.

Answer 6

using simultaneous equation
x + y = 3
x - y = -1
--------------
to find y, cancel "x" on both sides
u will have
+y = 3
-y =-1
---------
add then u will have
2y=4
divide both sides by 2
y=2
since y=2, replace y with 2 in equation 1 (x + y =3)
x +2 = 3
therefore x = 1

check!
plug in both equation x=1 and y =2
u will end up with 3 as the answer of the first equation and -1 as the answer of the second equation.

Answer 7

you can eliminate or substitute. i would eliminate. so add.. so in the next step it would be:
2x=2
x=1

because if you add these two together it would be like...
x + y = 3
+x - y = -1

THEN plug in 1 for x. so it would be. 1+y=3
y=2

hope it helps