How do you solve 4x-y=-6 and x-2y=-5?

1 Answer
Sep 30, 2015

The solutions are
#color(blue)(x=-1,y=2#

Explanation:

#color(blue)(4x)-y=-6#....equation #(1)#

#x-2y=-5#, multiplying this equation by #4#
#color(blue)(4x)-8y=-20#....equation #(2)#

Solving by elimination :
Subtracting equation #2# from #1#

#color(blue)(4x)-y=-6#
#-cancelcolor(blue)(4x)+8y=+20#

#7y=14#

#y=14/7#

#color(blue)(y=2#

Finding #x# by substituting #y# in equation #1#

#4x-y=-6#

#4x=-6+y#

#4x=-6+2#

#4x=-4#

#color(blue)(x=-1#