Question

i dont really get this.
solve each system of equations algebraically
y=x+4
y= -x

Answer 1

if \(y=-x\) and also \(y=x+4\) then since \(y=y\) you know \(-x=x+4\)

Answer 2

\[-x=x+4\]
\[-2x=4\]
\[x=-2\]