How do you solve #[(2x+y),(x-3y)]=[(5),(13)]#?

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Answer 1 · 2016-12-10T15:06:21

#(4,-3)#

#[(2x+y),(x-3y)]=[(5),(13)]#?

for this to be true

#2x+y=5-----(1)#

#x-3y=13-----(2)#

we now have a system of simultaneous eqns.

take eqn. #" "(1)#

#y=5-2x#

substitute into #" "(2)#

#x-3(5-2x)=13#

#x-15+6x=13#

#7x=28#

#x=4#

substitute into #" "(1)#

#2xx4+y=5#

#y=5-8=-3#

check in #" "(2)#

#4-(3xx(-3))=4-(-9)=4+9=13#

consistent

#:.(4,-3)#