Question

(-10)³+(7)³+(3)³ ,Without actual calculating the cubes, find the value of it.

Answer 1

Solution :

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We know that ,

If x + y + z = 0 , then

x³ + y³ + z³ = 3xyz

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Here,

x = (-10 ) , y = 7 , z = 3 ,

Now ,

x + y + z

= -10 + 7 + 3

= 0

Therefore ,

( -10 )³ + 7³ + 3³

= 3xyz

= 3× ( -10 ) × 7 × 3

= - 630

Therefore ,

The value of ( -10 )³ + 7³ + 3³

= - 630

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Answer 2

- 10 + 7 + 3 = 0

so,

x³ + y³ + z³ -3xyz

(-10)³+(7)³+(3)³ = 3(-10)(7)(3)

-1000 + 49 + 9 = -630

-630 = -630