How do you solve #3x+4y=-10# and #x-4y=2#?

Question

3811 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-03-21T08:31:26

#x = -2; y = -1#

First solve for #x# by adding the two equations:

#3x + 4y = -10#
+#x - 4y = 2#

This gives you:
#4x = -8#, so #x = -2#

Then you can solve for #y# by either plugging #-2# in for #x# or by multiplying the second equation by #-3# and adding the two equations again:

    #3x + 4y = -10#

+#-3(x - 4y) = 2*-3#

This gives:
#16y = -16#, so #y = -1#

You can verify your answer by plugging #-2# in for #x# and #-1# in for #y# in both equations.