How do you solve using elimination of #5x+4y+2=0 # and #4x-5y-23=0#?

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Answer 1 · 2018-03-08T14:21:58

#x=2#
#y=-3#

#5x+4y+2=0#

#=> 5x+4y=-2#

Multiply 5 both sides

#=> 25x+20y=-10# ----(1)

#4x-5y-23=0#

#=>4x-5y=23# ----(2)

Multiply 4 both sides

#=>16x-20y=92# ----(3)

#(1) + (3)#

#=> 25x+20y+16x-20y=-10+92#

#=> 41x=82#

#=> x=2#

Put this value in #(2)#

#=> 4(2)-5y=23#

#=> 8-5y=23#

#=> 8-23=5y#

#=> -15=5y#

#=> -3=y#