Вправи 101 - 200 » 103

Спростіть вираз: 1) y^2/(y^3-81) – y/(y+9) = y^2/((y-9)(y+9)) – y^(\y-9)/(y+9) = (y^2-y(y-9))/((y-9)(y+9)) = (y^2-y^2+9y)/((y-9)(y+9)) = 9y/(y^2-81); 2) n/(n-7) – n^2/(n^2-14n+49) = n^(\n-7)/(n-7) – n^2/((n-7)^2 ) = (n(n-7)-n^2 )/((n-7)^2 ) = (n^2-7n-n^2 )/((n-7)^2 ) = –7n/((n-7)^2 ).