Question 115632
Let's solve for y in the second equation




{{{x-y=13}}} Start with the given equation




{{{-y=13-x}}}Subtract x from both sides



{{{y=x-13}}} Multiply both sides by -1 to isolate y. This will change the sign of all of the terms on the right



Now since the slope of the first line is {{{m=1}}} and the slope of the second line is also {{{m=1}}}, these two lines are parallel. So they cannot be perpendicular.