Doubt by Vikrant
Solution :
(2x-5y)³-(2x+5y)³
[Using Identity :
(x+y)³ = x³+y³+3x²y+3xy² & (x-y)³ = x³-y³-3x²y+3xy² ]
(x+y)³ = x³+y³+3x²y+3xy² & (x-y)³ = x³-y³-3x²y+3xy² ]
= (2x)³-(5y)³-3(2x)²(5y)+3(2x)(5y)²-[(2x)³+(5y)³+3(2x)²(5y)+3(2x)(5y)²]
=(2x)³-(5y)³-3(2x)²(5y)+3(2x)(5y)²-(2x)³-(5y)³-3(2x)²(5y)-3(2x)(5y)²
= -(5y)³-(5y)³-3(2x)²(5y)-3(2x)²(5y)
= -2(5y)³-6(2x)²(5y)
= -2(5y)³-6(2x)²(5y)
= -250y³-120x²y OR -10y(25y²+12x²)