Science

Math

Humanities

... and beyond

Socratic Meta
Featured Answers

Topics

How do you solve the system $x + y = 14$ $x + y = 14$ and $- x + y = 16$ $-x + y = 16$ ?

1 Answer

Jul 19, 2016

$(x, y) = (- 1, 15)$ $color(green)((x,y)=(-1,15))$

Explanation:

Given
[1] $XXX x + y = 14$ $color(white)("XXX")x+y=14$
[2] $XXX - x + y = 16$ $color(white)("XXX")-x+y=16$

Adding [1] and [2] gives
[3] $XXX 2 y = 30 XX \to XX y = 15$ $color(white)("XXX")2y=30color(white)("XX")rarrcolor(white)("XX")y=15$

Subtracting [2] from [1] gives
[4] $XXX 2 x = - 2 XX \to XX x = - 1$ $color(white)("XXX")2x=-2color(white)("XX")rarrcolor(white)("XX")x=-1$

Related questions

See all questions in Systems Using Substitution

Impact of this question

1042 views around the world

You can reuse this answer
Creative Commons License