How do you solve the system of equations #7x - 2y = - 33# and #5x + 4y = 9# by elimination?

1 Answer
Nallasivam V
Mar 22, 2017

#x=-3#
#y=6#

Explanation:

#7x-2y=-33# -----------------------(1)
#5x+4y=9# ------------------------(2)

Multiply equation (1) with 2

#7x-2y=-33# -----------------------(1) #xx 2#

#14x-4y=-66# ----------------------(3)
#5x+4y=9# ------------------------(2) ---#(3)+(2)#
#19x=-57#
#x=(-57)/19=-3#

#x=-3#

Substitute #x=-3# in equation (1)

#7(-3)-2y=-33#
#-21-2y=-33#
#-2y=-33+21=-12#
#y=(-12)/(-2)=6#
#y=6#

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