Question

Answer 1

\(=\dfrac{5x-15+2x-4+x^2+3x}{\left(x-3\right)\left(x+3\right)}\)

\(=\dfrac{x^2+10x-19}{\left(x-3\right)\left(x+3\right)}\)

Answer 2

\(\dfrac{5}{x+3}+\dfrac{2x-4}{x^2-9}+\dfrac{x}{x-3}\\ =\dfrac{5\left(x-3\right)}{\left(x-3\right)\left(x+3\right)}+\dfrac{2x-4}{\left(x-3\right)\left(x+3\right)}+\dfrac{x\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}\\ =\dfrac{5x-15+2x-4+x^2+3x}{\left(x-3\right)\left(x+3\right)}\\ =\dfrac{x^2+10x-19}{\left(x-3\right)\left(x+3\right)}\)

Answer 3

Nhân tử chung là (x-3)(x+3)

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