(A = left( {frac{{x - 3}}{x} - frac{x}{{x - 3}} + frac{9}{{{x^2} - 3x}}} right):frac{{2x - 2}}{x})
Giải chi tiết:
(begin{array}{l},A = left( {frac{{x - 3}}{x} - frac{x}{{x - 3}} + frac{9}{{{x^2} - 3x}}} right):frac{{2x - 2}}{x},,,,,,A = left( {frac{{{{(x - 3)}^2}}}{{x(x - 3)}} - frac{{x.x}}{{x - 3}} + frac{9}{{{x^2} - 3x}}} right) cdot frac{x}{{2x - 2}},,,,,,A = left( {frac{{{{(x - 3)}^2} - {x^2} + 9}}{{x(x - 3)}}} right) cdot frac{x}{{2(x - 1)}},,,,,,A = frac{{{x^2} - 6x + 9 - {x^2} + 9}}{{x(x - 3)}} cdot frac{x}{{2(x - 1)}},,,,,A = frac{{ - 6x + 18}}{{x(x - 3)}} cdot frac{x}{{2(x - 1)}} = frac{{ - 6(x - 3)x}}{{x(x - 3).2.(x - 1)}} = frac{{ - 3}}{{x - 1}}end{array})