How do you solve #x+y= -1# and #x-y=3#?

Question

8650 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-03T18:10:09

#color(red)( x=1,y=-2)#

One way is to use the method of elimination.

Step 1. Enter the equations.

[1] #x+y=-1#
[2] #x-y=3#

Step 2. Add Equations 1 and 2.

#2x=2#

[3] #x=1#

Step 3. Substitute Equation 3 in Equation 2.

#x+y=-1#
#1+y=-1#

#y=-2#

Solution: #x=1,y=-2#

Check: Substitute the values of #x# and #y# in Equation 1.

#x+y=-1#
#1+(-2)=-1#
#1-2=-1#
#-1=-1#

It checks!

Our solution is correct.