How do you solve the following system?: #4x-y=-1 , 4x-3y=15 #

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Answer 1 · 2015-12-23T16:38:58

The solution for the system of equations is
#color(blue)(x=-9/4,y=-8#

#color(blue)(4x)-y=-1#.......equation #(1)#

#color(blue)(4x)-3y=15#.........equation #(2)#

Solving by elimination

Subtracting equation #2# from #1#

#cancelcolor(blue)(4x)-y=-1#
#cancel(-color(blue)(4x))+3y=-15#

#2y=-16#

#y=(-16)/2#

#color(blue)(y=-8#

Finding #x# by substituting #y# in equation #1#:
#4x-y=-1#

#4x=-1+y#

#4x=-1-8#

#4x=-9#

#color(blue)(x=-9/4#