How do solve the following linear system?: # 2x+7=-5y , 6x+4y=-1 #?

1 Answer
Jan 9, 2016

The solution for the system of equations is

#color(blue)(x=23/22#

#color(blue)(y=-20/11#

Explanation:

#2x+5y=-7# ,multiplying by #3#

#color(blue)(6x)+15y=-21# ........equation#1#

#color(blue)(6x)+4y=-1#...............equation#2#

Solving by elimination

Subtracting equation #2# from #1#:

#cancelcolor(blue)(6x)+15y=-21#
#-cancelcolor(blue)(6x)-4y=1 #

#11y=-20#

#color(blue)(y=-20/11#

Finding #x# from equation #1#:
#2x+5y=-7#

#2x=-7-5y#

#2x=-7-5 xx (-20/11)#

#2x=-7 +100/11#

#2x=-77/11 +100/11#

#2x=23/11#

#x=23/(11xx2)#

#color(blue)(x=23/22#