21/2-21/7 eching

$$2 \frac { 1 } { 2 } - 2 \frac { 1 } { 7 }$$

Baholash

$$\frac{5}{14}\approx 0,357142857$$

Yechim qadamlari

4 hosil qilish uchun 2 va 2 ni ko'paytirish.

$$\frac{4+1}{2}-\frac{2\times 7+1}{7}$$

5 olish uchun 4 va 1'ni qo'shing.

$$\frac{5}{2}-\frac{2\times 7+1}{7}$$

14 hosil qilish uchun 2 va 7 ni ko'paytirish.

$$\frac{5}{2}-\frac{14+1}{7}$$

15 olish uchun 14 va 1'ni qo'shing.

$$\frac{5}{2}-\frac{15}{7}$$

2 va 7 ning eng kichik umumiy karralisi 14 ga teng. \frac{5}{2} va \frac{15}{7} ni 14 maxraj bilan kasrlarga aylantirib oling.

$$\frac{35}{14}-\frac{30}{14}$$

\frac{35}{14} va \frac{30}{14} da bir xil maxraji bor, ularning suratini ayirish orqali ayiring.

$$\frac{35-30}{14}$$

5 olish uchun 35 dan 30 ni ayirish.

$$\frac{5}{14}$$

Omil

$$\frac{5}{2 \cdot 7} = 0,35714285714285715$$