How do solve the following linear system?: #-4x + 9y = 9 , x - 3y = -6 #?

1 Answer
Dec 30, 2015

Answer:

The solution for the system of equations is:

#color(blue)(x=9 ,y=5#

Explanation:

#color(blue)(-4x)+9y=9#..........equation #(1)#

#x -3y=-6#, multiplying by #4#
#color(blue)(4x) -12y=-24#.....equation #(2)#

Solving by elimination:
Adding both equations :

#cancelcolor(blue)(-4x)+9y=9#

#cancelcolor(blue)(4x) -12y=-24#

#-3y = -15#

#y=(-15)/(-3)#

#color(blue)(y=5#

Finding #x# from equation #2#:
#x -3y=-6#

#x =-6+3y#

#x =-6+3 xx 5#

#x =-6+15#

#color(blue)(x =9#