1. Представьте в виде дроби: а) c/9 + d/9; б) 5xy/p − 7xy/p; в) a/(4c) − (a − 3c)/(4c); г) (17b − 6)/(4b) − (5b + 2)/(4b).

1. \(\dfrac{c}{9}+\dfrac{d}{9}=\dfrac{c+d}{9}\).
2. \(\dfrac{5xy}{p}-\dfrac{7xy}{p}=\dfrac{5xy-7xy}{p}=\dfrac{-2xy}{p}\).
3. \(\dfrac{a}{4c}-\dfrac{a-3c}{4c}=\dfrac{a-(a-3c)}{4c}=\dfrac{3c}{4c}=\dfrac34\).
4. \(\dfrac{17b-6}{4b}-\dfrac{5b+2}{4b}=\dfrac{17b-6-(5b+2)}{4b}=\dfrac{12b-8}{4b}\).

Ответ: а) \(\dfrac{c+d}{9}\); б) \(-\dfrac{2xy}{p}\); в) \(\dfrac34\); г) \(\dfrac{12b-8}{4b}\).