a) Ta có: \(F=2x\left(x^2+3x+2\right)+x\left(5-2x^2-7x\right)+x^2-3\)
\(=2x^3+6x^2+4x+5x-2x^3-7x^2+x^2-3\)
\(=9x-3\)
b) Ta có: \(G=\left(3x+7\right)\left(2x+3\right)-\left(3x-5\right)\left(2x+11\right)\)
\(=6x^2+9x+14x+21-\left(6x^2+33x-10x-55\right)\)
\(=6x^2+23x+21-6x^2-23x+55\)
\(=76\)
c) Ta có: \(H=\left(x-2\right)\left(x^2+2x+4\right)-\left(x+2\right)\left(x^2-2x+4\right)\)
\(=x^3-8-\left(x^3+8\right)\)
\(=x^3-8-x^3-8\)
=-16
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