I can't figure out where I'm going wrong in solving this system of equations.

x^{2}+2xy-y^{2=}14

x^{2}-y^{2}= -16

Elimination

x^{2}+2xy-y^{2}=14

-x^{2}-0xy+y^{2}= 16

2xy=30

Substitution

x^{2}+30-y^{2}=14

x^{2}-y^{2}+30=14

-16+30=14

14=14

I keep getting results like this any way I try to substitute or rearrange the equations.