Question

Coefficient of xsquare in expansion of (x-2)whole cube

Answer 1

(x-2) the whole cube =(x-2)(x square +2x+4)
so coefficient of x square is 1

Answer 2

Answer:

Coefficient of x² in expansion of (x-2)³ is -6

Explanation:

Expansion of$(x-2)^{3}$

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we know the algebraic identity:

$\boxed{(a-b)^{3}=a^{3}-3a^{2}b+3ab^{2}-b^{3}}$

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= $x^{3}-3\times x^{2}\times 2+3 \times x \times 2^{2}-2^{3}$

= $x^{3}-6x^{2}+12x-8$

Now ,

Coefficient of x² in the expansion = -6

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