Question

x(x-3) = -1. Then find the value of x³(x³-18).

Answer 1

Step-by-step explanation:

here

x(x-3)=-1

x^2-3x+2=1

(x-1)(x-2)=1

therefore

x=2,x=3

now x^3(x^3-18)

then at x=2

-80

and at x=3

243

Answer 2

Answer:

-1 would be the answer.

Step-by-step explanation:

x(x-3) = -1

Take cube on both sides:

x³(x-3)³=-1

So,

x³(x³-27-9x²+27x) = -1

=>  Now, from given eqn x²-3x = -1 => x² = 3x-1

So, put the value of x² in the cubic eqn.

=> x³(x³-27-9(3x-1)+27x) = -1

=>x³(x³-27-27x+9+27x) = -1

=> x³(x³-18) = -1