Question

If x+ y = 3 and x = 3 then y​

Answer 1

Answer:

x3+y3=9 …(i)

x+y=3 …(ii)

Cubing the second equation , we get

(x+y)3=27

x3+y3+3xy(x+y)=27

9+3xy(3)=27

1+xy=3

xy=2

x=2y

From (ii)

2y+y=3

2+y2=3y

y2−3y+2=0

(y−1)(y−2)=0

y=1 (or) y=2

⟹x=2 (or) x=1

Consider any one pair out of (2,1) , (1,2) , as the numbers are same …

So , x4+y4

=(2)4+(1)4

=16+1

=17.

∴x4+y4=17

Hope this answer helps you , Have a good day ahead …