How do you solve the system of equations #2x-y=71# and #3y=x# using substitution?

1 Answer
Feb 17, 2017

#(142/5 , 71/5)#

Explanation:

#2x-y=71# and #3y=x#

you just substitute one equation into the other
since #x=3y# you can just insert that into #2x-y=71#

#2(3y)-y=71#
#6y-6=71#
#5y=71#
#y=71/5#

then we plug this y-value into either equation
#2x-71/5=71#
#2x=284/5#
#x=284/10=142/5#

#(142/5 , 71/5)#