How do you solve #4x+7y=6# and #6x+5y=20# using elimination?

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Answer 1 · 2014-11-09T18:07:34

#{(4x+7y=6),(6x+5y=20):}#

by multiplying the first equation by #3# and the second equation by #2#,

#=>{(12x+21y=18),(12x+10y=40):}#

by subtracting the second equation from the first equation,

#=>11y=-22#

by dividing by #11#,

#=>y=-2#

By plugging #y=-2# into the first equation of the original system,

#4x+7(-2)=6 => 4x-14=6#

by adding #14#,

#=> 4x=20#

by dividing by #4#,

#=> x=5#

Hence, the solution is #(x,y)=(5,-2)#.

I hope that this was helpful.