Question

using suitable identities, find 8m³-y³​

Answer 1

Answer:

Using Formula (x+a)(x+b) = x

2

+(a+b)x+ab

Writing 33 as 30+3 and 27 as 30−3

⇒ (30+3)(30−3) = 30

2

+[3+(−3)]30+(3)(−3)

= 900+[(0)30]−9

= 891

Hence the answer is 891

Answer 2

Step-by-step explanation:

*(2m - y )³*

*{using identity (a-b)³= a³-b³-3ab(a-b)}*

*(2m)³-(y)³-3(2m)(y)[2m-y]*

*8m³-y³-6my (2m-y)*

*8m³- y³ -6m²y + 6my³*