How do you solve -4x+9y=9 and x-3y= -6?

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Answer 1 · 2018-03-15T15:49:17

See below.

#4x+9y=9 " " " "(1) #

#x-3y= -6 " " " "(2)#

From equation #(2)#

#x-3y=-6#

#=> x = -6+3y " " " "(3)#

Substituting in equation #(1)#

#=> 4(3y-6)+9y=9#

#=>12y-24+9y=9#

#=>21y=9+24#

#=>21=33#

#=>y=33/21#

#=>y=11/7 #

Substituting the value of #y# in equation #(2)#

#x=3y-6#

#=> x=3(11/7)-6#

#=> x=33/7-6#

#=> x = (33-42)/7#

#=> x=-9/7#

So

#x=-9/7 and y=11/7#