How do you solve the system $x+y=4$ and $x-y=2$ ?

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Answer 1 · 2015-03-27T23:16:48

By adding the two equations together, the $y$ variable is reduced to $0$ leaving an equation with only the $x$ variable which is easy to solve.

$(x+y=4)$
$+ (x-y=2)$

$2x =6$ which implies $x=3$

Substituting $x=3$ back into the first equation
(3) + y = 4 $implies$ y= 1#

The given equations intersect at $(x,y)=(3,1)$

How do you solve the system x+y=4x+y=4 and x-y=2x-y=2?