How do you solve #3x-2y=-4# and #3x+2y=16# using substitution?

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Answer 1 · 2018-05-21T07:13:15

Find 3 x using the first equation and put the value in the second

The first equation could be arranged

#3x-2y = -4#

#3x = 2y-4#

Now put this into the second equation

#3x + 2y = 16# (Instead of 3x, put the value found above)

#2y -4 + 2y = 16#

#4y = 16+ 4#

#4y = 20#

#y=5#

Now you can using x (using the fist equation)

#3x = 2y -4# (now we know #y=5#)

#3x = 2times5 -4#

#3x = 10-4#

#3x = 6#

#x=6/3 = 2#

Your solution:

#x=2 and #y=5#