How do you solve the system of equations #2x + 7y = 13# and #- 4x + y = - 11#?

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Answer 1 · 2017-07-16T16:05:15

After adding first equation twice into second one.

#2*(2x+7y)-4x+y=2*13-11#

#4x+14y-4x+y=26-11#

#15y=15#

#y=1#. Thus, #2x+7*1=11# or #2x=4#, so #x=2#.

1) Add first equation twice into second one.

2) Solve it for y.

3) Find x.