How do you solve the system using elimination #c + 2d = -2# and #-2c - 5d = 3#?

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Answer 1 · 2015-06-08T17:23:52

#c +2d = -2# , multiplying this equation with #2#
#2c +4d = -4# ..........equation #(1)#

#−2c−5d=3# ...............equation #(2)#

Adding the two equations to cancel #color(red)(2c#

#cancelcolor(red)(2c) +4d = -4#
# cancelcolor(red)(-2c) - 5d =3#

#-d = -1#
# color(red)(d=1#

Substituting #d# in the first equation to find #c#

# c = -2 -2d#
# c = -2-2.(1)#
#color(red)( c = -4#

The solutions for the system of equations are:
# color(red)( d=1, c=-4#