Question 53

If $$(x - 7)^3 + (x - 8)^3 + (x + 6)^3 = 3(x - 7)(x - 8)(x + 6)$$, then what is the value of $$x$$ ?

Solution

We know that, If $$ a^3 +b^3 + c^3 = 3abc$$ then, a + b+ c= 0

Therefore,

We will have, x - 7 + x - 8 + x+ 6 =0

therefore 3x = 9

and x= 3

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