plesae solve the question tommorow not today now solve the question
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Answer is 18(4 - xy)
Solution:
Since, x+y+2=4
or x + y = 2 ...........(1)
Also, we can write
(x + y)^2 = 2^2
or x^2 + 2xy + y^2 = 4
or x^2 + y^2 = 4 - 2xy ............(2)
Also, 4x + 4y = 2*4
or -4x -4y = -8 ............(3)
Now,
x^3 + y^3 - 12xy + 64
= x^3 + y^3 + 4^3 - 3xy*4
= (x + y + 4) (x^2 + y^2 + 4^2 - xy - 4y - 4x) .....(using indices a^3+b^3+c^3-3abc)
= (2 + 4) (4 - 2xy + 16 - xy -8) ...........(from 1,2&3)
= 6 (20 - 3xy - 8)
= 6 (12 - 3xy)
= 18 (4 - xy)
Solution:
Since, x+y+2=4
or x + y = 2 ...........(1)
Also, we can write
(x + y)^2 = 2^2
or x^2 + 2xy + y^2 = 4
or x^2 + y^2 = 4 - 2xy ............(2)
Also, 4x + 4y = 2*4
or -4x -4y = -8 ............(3)
Now,
x^3 + y^3 - 12xy + 64
= x^3 + y^3 + 4^3 - 3xy*4
= (x + y + 4) (x^2 + y^2 + 4^2 - xy - 4y - 4x) .....(using indices a^3+b^3+c^3-3abc)
= (2 + 4) (4 - 2xy + 16 - xy -8) ...........(from 1,2&3)
= 6 (20 - 3xy - 8)
= 6 (12 - 3xy)
= 18 (4 - xy)
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