Question

pls help me in this question.. std9 no spam...

Answer 1

${x}^{2} + 2xy + {y}^{2} - ( {a}^{2} - 2ab + {b}^{2} ) \\ = {(x + y)}^{2} - {(a - b)}^{2} \\ = (x + y + a - b)(x + y - a + b)$