How do you solve the following system: #2x + y = 8 , x-10y=10 #?

1 Answer
Jan 15, 2016

Answer:

The solution is
#color(blue)(x = 30/7 #
#color(blue)(y = -4/7#

Explanation:

#color(blue)(2x) +y = 8#.........equation #(1)#

#x -10y = 10#, multiplying by #2#
#color(blue)(2x) -20y =20#....equation #(2)#

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

#cancelcolor(blue)(2x) +y = 8#
#-cancelcolor(blue)(2x) +20y =-20#

#21y = -12#

#y = -12/21#

#color(blue)(y = -4/7#

Finding #x# from equation #2#:
#x -10y = 10#

#x = 10+ 10y #

#x = 10+ 10 xx -4/7 #

#x = 10 -40/7 #

#x = 70/7 -40/7 #

#color(blue)(x = 30/7 #