If x-y = 3, then what is the value of x³-y³-9xy?
সমাধান
সঠিক উত্তর: Option D
দেওয়া আছে ,x-y=3
x³-y³-9xy=(x)³-(y)³-9xy
=(x-y)³+3.xy.(x-y)-9xy
=(3)³+3.xy.3-9xy
=27+9xy-9xy
=27
x³-y³-9xy=(x)³-(y)³-9xy
=(x-y)³+3.xy.(x-y)-9xy
=(3)³+3.xy.3-9xy
=27+9xy-9xy
=27
