How do you solve 5x - 4y = 9 and 3 - 2y = -x?

1 Answer
Aug 22, 2015

Answer:

The solutions are
#color(blue)(x=5,y=4#

Explanation:

#5x - color(blue)(4y) = 9# ......equation #1#

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

Solving by elimination
Adding equations #1# and #2#

#5x - cancelcolor(blue)(4y) = 9#
# -2x+cancelcolor(blue)(4y) = 6#

#3x=15#
#color(blue)(x=5#

Substituting #x# in equation #2# to find #y#
# 3 - 2y = -x#
# 3 +x=2y#
# 3 +5=2y#
#y=8/2#
#color(blue)(y=4#