Question 634338
1)-x^2-y^2=?
x=-2,y=-3

{{{-(-2)^2-(-3)^2}}}


-4-9=-13


2)(c^2-2*c*d+d^2)/(c-d)^2=?
c=+3,d=-3

{{{(c-d)^2/(c-d)^2}}}

=1