Помогите! Выполните действия m-3n / 8n (m+n) - m+3n / 8n (m-n) ; x^2-x+1 - x^3 / x+1; 3c+7 / c^2+7c + c-7 / 7c + 49; Распишите действия подробнее

1) (m-3n) / 8n (m+n) - (m+3n) / 8n (m-n) = [ (m-3n) (m-n) - (m+3n) (m+n) [/8n (m-n) (m+n) =

= (m²-mn-3mn+3n²-m²-mn-3mn-3n²) / 8n (m-n) (m+n) = - 8mn/8n (m-n) (m+n) = = n / (n-m)

2) x²-x+1 - x³ / (x+1) = (x³+x²-x²-x+x+1-x³) / (x+1) = 1 / (x+1)

3) (3c+7) / c (c+7) + (c-7) / 7 (c+7) = (21c+49+c²-7c) / 7c (c+7) = (c²+14c+49) / 7c (c+7) = (c+7) ²/7c (c+7) = (c+7) / 7c