x +y+z =12 and x²+ y²+z² =70 then find the value of x³ + y³ +z³-3xyz
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x³ + y³ +z³-3xyz=[x+y+z][x²+y²+z²-xy-yz-zx]
wkt [x+y+z]²=x²+y²+z²+2xy+2yz+2zx
[12]²=70+2[xy+yz+zx]
2[xy+yz+zx]=144-70
xy+yz+zx=74/2⇒37
x³ + y³ +z³-3xyz=[x+y+z][x²+y²+z²-xy-yz-zx]
[12][70-37] =12×33=396
x³ + y³ +z³-3xyz=396
hope it helps you
wkt [x+y+z]²=x²+y²+z²+2xy+2yz+2zx
[12]²=70+2[xy+yz+zx]
2[xy+yz+zx]=144-70
xy+yz+zx=74/2⇒37
x³ + y³ +z³-3xyz=[x+y+z][x²+y²+z²-xy-yz-zx]
[12][70-37] =12×33=396
x³ + y³ +z³-3xyz=396
hope it helps you
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