Question

if x+y+z=4 and x²+y²+z²=38 what is x³+y+³z³= ​

Answer 1

Step-by-step explanation:

(x+y+z)²=x²+y²+z²+2(xy+yz+xz)

(4)² =38+2(xy+yz+xz)

16. =38+2(xy+yz+xz)

16–38= 2(xy+yz+xz)

-22. = 2(xy+yz+xz)

-22/2. =xy+yz+xz

-11. =xy+yz+xz. [xy+yz+xz=11]

(x+y+z)³= (x+y+z)[(x²+y²+z²–xy+yz+xz)]

=. (-11) [ 38–(–11)]

=. -11[38+11]

= -11×49 = –539