How do I solve (x+y)2-(9xy-6x2)=

Question

(x+y)2-(9xy-6x2)=

Answer 1

x²+2xy+y²-9xy+6x²=7x²-7xy+y² after expanding parentheses.

This is probably the expected answer, because the factors from now on are irrational.

y²-7xy+7x² can be factorised with irrational factors:

(y²-7xy+49x²/4)+(7-49/4)x²=

(y-7x/2)²-21x²/4, difference of two squares:

(y-7x/2+x√21/2)(y-7x/2-x√21/2),

(y-½x(7-√21))(y-½x(7+√21)),

(y-1.2087x)(y-5.7913x) approx.