Question

giúp mk nha khẩn cáp

Answer 1

\(=\dfrac{1}{\left(x+1\right)\left(x+3\right)}-\dfrac{1}{\left(x+1\right)\left(x+2\right)}\)

\(=\dfrac{x+2-x-3}{\left(x+1\right)\left(x+3\right)\left(x+2\right)}=\dfrac{-1}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)

Answer 2

\(\dfrac{1}{x^2+4x+3}-\dfrac{1}{x^2+3x+2}\)

\(=\dfrac{1}{x^2+3x+x+3}-\dfrac{1}{x^2+2x+x+2}\)

\(=\dfrac{1}{x\left(x+3\right)+\left(x+3\right)}-\dfrac{1}{x\left(x+2\right)+\left(x+2\right)}\)

\(=\dfrac{1}{\left(x+1\right)\left(x+3\right)}-\dfrac{1}{\left(x+1\right)\left(x+2\right)}\)

\(=\dfrac{x+2}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}-\dfrac{x+3}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)

\(=\dfrac{x+2-x-3}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)

\(=\dfrac{-1}{\left(x+1\right)\left(x+2\right)\left(x+3\right)}\)