A) 23
B) 55
C) 69
D) 81
Correct Answer: C
Solution :
[c] \[x+{{x}^{2}}y+x{{y}^{2}}+y=63\] \[\Rightarrow \,(x+y)(1+xy)=63\] \[\Rightarrow \,(x+y)(1+6)=63\,\,or\,\,x+y=9\] \[\therefore \,\,{{x}^{2}}+{{y}^{2}}={{(x+y)}^{2}}-2xy=81-2\times 6=69.\] :. x2 + v2 - (x + yY ~- 2.XV - 81 - 2 x 6 == 69.You need to login to perform this action.
You will be redirected in
3 sec