Need help with solving 4x-y=9, x-3y=16?

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Answer 1 · 2018-06-03T04:15:43

#x# is equal to #1# and #y# is equal to #-5#.

#{(4x-y=9), (x-3y=16) :}#

Do

#4x-y=9 #
#(x-3y)xx4=16xx4#

So

#{(4x-y=9), (4x-12y=64) :}#

Subtract the two equations

#0x+11y= -55#

#11y=-55#

#y=-5#

Replace #y# in the first equation

#4x-y=9#

#4x-(-5)=9#

#4x+5=9#

#4x=4#

#x=1#