Question

If X+y=3and xy=18 find the value. Of x³+y³​

Answer 1

We know :

x + y = 3

xy = 18

Then,

(x + y)³ = x³ + y³ + 3xy(x + y)

Now substituiting the values..

3³ = x³ + y³ + 3×18×3

27 = x³ + y³ + 162

x³ + y³ = 162 - 27

= 135