Question

3. Find the value of x3 + y + z3 - 3xyz if x2 + y2 + z = 83 and x
y + z = 15​

Answer 1

Step-by-step explanation:

(x+y+z)²=x²+y²+z²+2(xy+yz+zx)

(15)²=83+2(xy+yz+zx)

225-83=2(xy+yz+zx)

142=2(xy+yz+zx)

xy+yz+zx=71

x³+y³+z³-3xyz

=(x+y+z)(x²+y²+z²-xy-yz-zx)

=15(83-71)

=15.12

=180