How do you solve the system #8x + 7y = -16 # and #6x - 3y = -12#?

1 Answer
Jun 18, 2015

Answer:

# color(red)( x = -2, y=0#

Explanation:

Solving by elimination :

#8x + 7y = -16 #
Multiplying the equation by #3# :
#color(red)(24x )+ 21y = -48#...................EQUATION #1#

#6x - 3y = -12#
Multiplying the equation by #4#:
#color(red)(24x) - 12y = -48# ..................EQUATION #2#
The purpose of this multiplication was to create a common term #24x# in both of the equations to enable elimination

Subtracting equation #2# from #1#
#color(red)(24x )+ 21y = -48#
#-color(red)(24x) + 12y = +48#
# 0 + 33y =0 #
# y = 0#

Finding #x#
#8x = -16 - 7y#
#8x = -16 -0#
#x = -2#