How do you solve #3x -y = 4# and #x + 2y = 13#?

1 Answer
Dec 21, 2015

Answer:

The solution for the system of equations is
#color(blue)(x=3, y=5#

Explanation:

#3x-y=4#, multiplying by #2#
#6x-color(blue)(2y)=8#.....equation #1#

#x +color(blue)(2y)=13#....equation #2#

Solving by elimination

Adding equations #1# and #2#

#6x-cancelcolor(blue)(2y)=8#

#x +cancelcolor(blue)(2y)=13#

#7x=21#

#x=21/7#

#color(blue)(x=3#

Finding #y# from equation #1#

#3x-y=4#

#3x-4=y#

#3 xx color(blue)(3)-4=y#

#9 -4=y#

#color(blue)(y=5#