Вариант В1. 3. Вычислите: а) 7/220 + 17/330; б) 0,88 − 2/15; в) (1/6 + 5/18) − (1/18 + 1/24).

1. а) \(\frac{7}{220}+\frac{17}{330}=\frac{21}{660}+\frac{34}{660}=\frac{55}{660}=\frac{1}{12}\).
2. б) \(0{,}88-\frac{2}{15}=\frac{22}{25}-\frac{2}{15}=\frac{66}{75}-\frac{10}{75}=\frac{56}{75}\).
3. в) \(\left(\frac16+\frac5{18}\right)-\left(\frac1{18}+\frac1{24}\right)=\left(\frac3{18}+\frac5{18}\right)-\left(\frac4{72}+\frac3{72}\right)=\frac49-\frac7{72}=\frac{32}{72}-\frac7{72}=\frac{25}{72}\).

Ответ: а) \(\frac{1}{12}\); б) \(\frac{56}{75}\); в) \(\frac{25}{72}\).