Question

if X + Y - 1 is zero prove that x cube + y cube + 3 x y is 1​

Answer 1

Answer:

x+y-1=0

x+y=1.........eqⁿ(i)

cubing on both sides

(x+y)³ = 1³

x³+y³+3xy(x+y)=1

from eqⁿ(i) value of (x+y) is 1

so x³+y³+3xy=1