How do you solve the system #x+y=2# and #x-y=4#?

1 Answer
Mar 8, 2016

Answer:

The solution is #( 3, -1 )#

Explanation:

In this case the solution can be found by using the "elimination method". Looking at the two equations I see that you have #+y# in equation one and #-y# in equation two. By adding the two equations together I will "eliminate" the #y# variable and then I can solve for # x #.

# x + y = 2#
#x - y = 4#

Add the two equation together and get:

#2x = 6#

x = 3 Now substitute # 3 # for # x # in either equation and solve for #y#

#x + y = 2 #
#3 + y = 2#
# y = - 1#
The solution is #(3 , -1 )#
Now you can, and should, verify that your answer is correct by substituting the solution in the second equation. If it works out, you have the correct answer.
# x - y = 4#
#3 - (-1) =4#
# 4 = 4 #