# If x + y = 3, then what is the value of x 3 + y 3 + 9xy? X+y=3 Wh

| If x + y = 3, then what is the value of x

^{3}+ y^{3}+ 9xy?A. 15

B. 81

C. 27

D. 9

Please scroll down to ** see the correct answer ** and ** solution guide.**

### Right Answer is: C

#### SOLUTION

X+y=3

Whole cube on both side

X^{3} +y^{3}+3xy(x+y)=27

X^{3} +y^{3} +3xy(3)=27

X^{3} +y^{3} +9xy=27