if X + Y + Z is equal to 10 and X square + Y square + Z square is equal to 40 find X Y + y z + exact and x cube + y cube + Z cube minus 3 x y z
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hope it helps
Step-by-step explanation:
hey mate here is ur answer
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xy+yz+zx=30
x³+y³+z³-3xyz=100
Step-by-step explanation:
Given:
x+y+z=10
x²+y²+z²=40.
We know that
(a+b+c)²=a²+b²+c²+2(ab+bc+ca)
x+y+z=10
Take square on both sides
⇒(x+y+z)²=10²
⇒x²+y²+z²+2(xy+yz+zx)=100
Substituting the value x²+y²+z²=40
⇒40+2(xy+yz+zx)=100
⇒2(xy+yz+zx)=100-40
⇒2(xy+yz+zx)=60
Cross multiplying
⇒xy+yz+zx=30
We know that
x³+y³+z³=(x+y+z)(x²+y²+z²-xy-yz-zx)+3xyz
⇒x³+y³+z³-3xyz=(x+y+z)(x²+y²+z²-(xy+yz+zx))
Substituting the known values
⇒x³+y³+z³-3xyz=10(40-30)
⇒x³+y³+z³-3xyz=10(10)
⇒x³+y³+z³-3xyz=100
Learn More:
If X + Y + Z is equal to 1, xy + yz plus zx is equal to -1 and x y z is equal to -1, find the value of x cube + y cube + Z cube
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