How do you solve #3y=-2x, y=x-5# by substitution?

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Answer 1 · 2016-12-06T23:42:33

#x = 3# and #y = -2#

Step 1) Because the second equation is already solved for #y# we can substitute #x - 5# for #y# in the first equation and solve for #x#:

#3(x - 5) = -2x#

#3x - 15 = -2x#

#3x - 15 + 15 + 2x = -2x + 15 + 2x#

#3x - 0 + 2x = 0 +15#

#5x = 15#

#(5x)/5 = 15/5#

#x = 3#

Step 2) Substitute #3# for #x# in the second equation and calculate #y#:

#y = 3 - 5#

#y = -2#