5/21*15/7+2/21*5/7 eching

$$\frac{ 5 }{ 21 } \times 1 \frac{ 5 }{ 7 } + \frac{ 2 }{ 21 } \times \frac{ 5 }{ 7 }$$

Baholash

$$\frac{10}{21}\approx 0,476190476$$

Yechim qadamlari

7 hosil qilish uchun 1 va 7 ni ko'paytirish.

$$\frac{5}{21}\times \frac{7+5}{7}+\frac{2}{21}\times \frac{5}{7}$$

12 olish uchun 7 va 5'ni qo'shing.

$$\frac{5}{21}\times \frac{12}{7}+\frac{2}{21}\times \frac{5}{7}$$

Suratni maxrajga va maxrajini suratga ko‘paytirish orqali \frac{5}{21} ni \frac{12}{7} ga ko‘paytiring.

$$\frac{5\times 12}{21\times 7}+\frac{2}{21}\times \frac{5}{7}$$

\frac{5\times 12}{21\times 7} kasridagi ko‘paytirishlarni bajaring.

$$\frac{60}{147}+\frac{2}{21}\times \frac{5}{7}$$

\frac{60}{147} ulushini 3 ni chiqarib, bekor qilish hisobiga eng past shartlarga kamaytiring.

$$\frac{20}{49}+\frac{2}{21}\times \frac{5}{7}$$

Suratni maxrajga va maxrajini suratga ko‘paytirish orqali \frac{2}{21} ni \frac{5}{7} ga ko‘paytiring.

$$\frac{20}{49}+\frac{2\times 5}{21\times 7}$$

\frac{2\times 5}{21\times 7} kasridagi ko‘paytirishlarni bajaring.

$$\frac{20}{49}+\frac{10}{147}$$

49 va 147 ning eng kichik umumiy karralisi 147 ga teng. \frac{20}{49} va \frac{10}{147} ni 147 maxraj bilan kasrlarga aylantirib oling.

$$\frac{60}{147}+\frac{10}{147}$$

\frac{60}{147} va \frac{10}{147} da bir xil maxraji bor, ularning suratini qo‘shish orqali qo‘shing.

$$\frac{60+10}{147}$$

70 olish uchun 60 va 10'ni qo'shing.

$$\frac{70}{147}$$

\frac{70}{147} ulushini 7 ni chiqarib, bekor qilish hisobiga eng past shartlarga kamaytiring.

$$\frac{10}{21}$$

Omil

$$\frac{2 \cdot 5}{3 \cdot 7} = 0,47619047619047616$$