solving systems of linear equations help please!

Question

chrisplusian · Answer

x+y=7, and x-y=1 I missed class and don't know how to do these can you not just answer but also explain please

anonymous · Answer

solve for x in then substitute it into the other equation. x=7-y so then (7-y)-y=1 solve for y and you get 4 then plug that into either equation to find x.

anonymous · Answer

in one equation*

anonymous · Answer

$$x+y=7[1]$$
$$x-y=1[2]$$
Elimination method.
$$[1]-[2]$$
$$(x+y)-(x-y)=(7)-(1)$$
$$x+y-x--y=7-1$$
x's cancel out.
$$y+y=6$$
$$2y=6$$
$$y=3$$
TO find the x-value, substitute the y-value into one of the two equations given above by me (ie. [1] or [2])

chrisplusian · Answer

thank you for your help