Question

Factorise : 9-y²+2xy-x²

Answer 1

Answer:

$9 - (y {}^{2} - 2xy + x {}^{2} )$

$9 - ( x - y) {}^{2}$

$3 {}^{2} - (x - y) {}^{2}$

$(3 - (x - y))(3 + x - y)$

$3 - x + y)(3 + x - y)$