Chọn đáp án đúng.

\(\dfrac{x}{{x + 2}}\)

\(\dfrac{{x + 2}}{x}\)

\( - \dfrac{{x + 2}}{x}\)

\( - \dfrac{x}{{x + 2}}\)

\(\dfrac{3}{2}\)

\(\dfrac{3}{{2(x - 4)}}\)

\(\dfrac{{ - 3}}{2}\)

\(\dfrac{{ - 3}}{{2(x - 4)}}\)

\(\dfrac{{ - 7{x^2}z}}{{3y}}\)

\(\dfrac{{7{x^2}z}}{3}\)

\(\dfrac{{ - 7xz}}{{3y}}\)

\(\dfrac{{ - 7{x^2}}}{{3y}}\)

\(\dfrac{{3{x^2} - {y^2}}}{{50}}\)

\(\dfrac{{3\left( {{x^2} + {y^2}} \right)}}{{50}}\)

\(\dfrac{{3\left( {{x^2} - {y^2}} \right)}}{{50}}\)

\(\dfrac{{3{x^2} + {y^2}}}{{50}}\)

\(\dfrac{3}{{x + 2}}\)

\(\dfrac{{ - 3}}{{x + 2}}\)

\(\dfrac{1}{{x + 2}}\)

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

\({x^2} - x + 1\)

\(x + 1\)

\(3\)

\({x^3} + 1\)