Question

Factorise the question(ticked ones only). I WANT ANSWER WITH FULL EXPLANATION.

Answer 1

hope this helps

in 17) formula used is
${x}^{2} - {y}^{2} = (x + y)(x - y)$

18) formula used is
${x}^{2} + {y}^{2} + 2xy = (x + y)^{2}$
and (x²-y²) = (x+y)(x-y)


19) formula used is

a²+b²-2ab = (a-b)²

and (a²-b²) = (a+b)(a-b)


20) a²+b²+2ab = (a+b)²

and a²-b² = (a+b)(a-b)



hope this helps