How do you solve 5x - 3y = -20 and -3x + 6y = 12?

1 Answer
Sep 15, 2015

Answer:

The solution is
#color(blue)(x=-4, y=0#

Explanation:

# 5x - 3y = -20 #, multiplying this equation by #2#
#10x - color(blue)(6y) = -40 #......equation #1#

#-3x + color(blue)(6y) = 12#......equation #2#

Solving the equation by elimination .

Adding equations #1# and #2# results in elimination of #color(blue)(6y#

#10x - cancelcolor(blue)(6y) = -40 #
#-3x + cancelcolor(blue)(6y) = 12#

#7x= -28#

#x= -28/7#

#color(blue)(x=-4#

Substituting #x# in equation #1# to find #y#
# 5x - 3y = -20 #

# 5x +20 = 3y #

# 5*(-4) +20 = 3y #

# -20 +20 = 3y #

#3y=0#

#color(blue)(y=0#