Question

math class 9th Rs aggrawal book Ka questions hai bhai Exercise 3b ka​

Answer 1

Answer:

21)

a³+3a²b+3ab²+b³-a-b

23)

(a+b)²-(a-b)²

here a=x and b=y

used indentity

25)

a-b-{a²+2ab+b²}

a-b-a²-2ab-b²