How do you determine the solution in terms of a system of linear equations for #-2x + 3y = 14#, #x - 4y = 11#?

1 Answer
Alan P.
Oct 6, 2015

#(x,y) = (-17.8,-7.2)#

Explanation:

[1]#color(white)("XXX")-2x+3y=14#
[2]#color(white)("XXX")x-4y=11#

Multiply [2] by #2#
[3]#color(white)("XXX")2x-8y=22#

Add [1] and [3]
[4]#color(white)("XXX")-5y=36#

Divide [4] by #(-5)#
[6]#color(white)("XXX")y = -36/5=-7.2#

Substituting #(7.2)# for #y# in [1]
[7]#color(white)("XXX")-2x+3(-7.2)=14#

[8]#color(white)("XXX")-2x-21.6=14#

[9]#color(white)("XXX")-2x=35.6#

[10]#color(white)("XXX")x = -17.8#

Related questions
See all questions in Linear Systems with Multiplication
Impact of this question
1235 views around the world
You can reuse this answer
Creative Commons License