Question

Tính

(x+2)(9x²-6x+4)

Answer 1

Sửa đề :

\(\left(3x+2\right)\left(9x^2-6x+4\right)\)

\(=\left(3x\right)^3-2^3\)

Answer 2

(x+2)(9x^2-6x+4)

= 9^3-6x^2+4x+18x^2-12x+8

=9x^3+12x^2-8x+8

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Answer 3

\(\left(x+2\right)\left(9x^2-6x+4\right)\)

\(=x\left(9x^2-6x+4\right)+2\left(9x^2-6x+4\right)\)

\(=9x^3-6x^2+4x+18x^2-12x+8\)

\(=9x^3+\left(18x^2-6x^2\right)-\left(12x-4x\right)+8\)

\(=9x^3+12x^2-8x+8\)

Answer 4

\(\left(x+2\right).\left(9x^2-6x+4\right)\)

=\(\left(x+2\right).\left(9x^2-6x+4\right)+2\left(9x^2-6x+4\right)\)

=\(9x^3-6x^2+4x+18x^2-12x+8\)

=\(9x^3+\left(18x^2-6x^2\right)-\left(12x-4x\right)+8\)

=\(\left(9x^3\right)+12x^2-8x+8\)