РОЗДІЛ 2. Раціональні вирази - Вправи 50 - 200 » 147 (1-5)

147. Спростіть вираз: 1) 9/(3+ x) – x^2/(3+ x) = 〖9- x〗^2/(3+ x) = ((3- x)(3+x))/(3+ x) = 3 – x; 2) 25/(x-5) – x^2/(x-5) = 〖25- x〗^2/(x-5) = ((5- x)(5+ x))/(x-5) = (-(x-5)(5+ x))/(x-5) = –5 – x; 3) 36/(6+ c) – c^2/(6+ c) = 〖36- c〗^2/(6+ c) = ((6- c)(6+ c))/(6+ c) = 6 – c; 4) 7/(x^2-49) – x/(x^2-49) = (7- x)/(x^2-49) = (7- x)/((x-7)(x+7)) = (-(x-7))/((x-7)(x+7)) = – 1/(x+7); 5) y^2/(y+1) + (1+2y)/(y+1) = (y^2+1+2y)/(y+1) = 〖(y+1)〗^2/(y+1) = y + 1;