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создана: 23.01.2017 в 03:28 ................................................
oxydoc79 :
выполнить действие:
(((x-1)*x)/((x^2)-25))-(((x-3)/(x+5)))-(((x-2)/(5-x)))
x(x–1) / (x2–25) – (x-3)/(x+5) – (x-2)/(5-x) =
= x(x–1) / [(x–5)(x+5)] – (x-3)/(x+5) + (x-2)/(x-5) =
= x(x–1) / [(x–5)(x+5)] – (x-3)(x-5)/[(x–5)(x+5)] + (x-2)(x+5)/[(x–5)(x+5)] =
= [x(x–1) – (x-3)(x-5) + (x-2)(x+5)] / [(x–5)(x+5)] =
= [x2–x – (x2–8x+15) + (x2+3x-10)] / [(x–5)(x+5)] =
= [x2–x – x2+8x–15 + x2+3x-10] / [(x–5)(x+5)] = [x2–10x–25] / [(x–5)(x+5)]=
= (x–5)2 / [(x–5)(x+5)] = (x–5)/(x+5)
