Question

what\:bionomial\:do\:you\:have\:to\:add\:to\:the\:polynomial\:x^2+y^2-2xy+1\:to\:get\:a\:polynomial\:that\:does\:not\:contain\:the\:variable\:y

Answer 1

Add 2xy - y^2.

Reason: x^2 + y^2 - 2xy + 1 + (2xy - y^2) = x^2 + 1,

which contains no y.