5/21*15/7+2/4*3/7 eching

$$\frac { 5 } { 21 } \times 1 \frac { 5 } { 7 } + \frac { 2 } { 4 } \times \frac { 3 } { 7 }$$

Baholash

$$\frac{61}{98}\approx 0,62244898$$

Yechim qadamlari

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

$$\frac{5}{21}\times \frac{7+5}{7}+\frac{2}{4}\times \frac{3}{7}$$

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

$$\frac{5}{21}\times \frac{12}{7}+\frac{2}{4}\times \frac{3}{7}$$

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

$$\frac{5\times 12}{21\times 7}+\frac{2}{4}\times \frac{3}{7}$$

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

$$\frac{60}{147}+\frac{2}{4}\times \frac{3}{7}$$

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

$$\frac{20}{49}+\frac{2}{4}\times \frac{3}{7}$$

\frac{2}{4} ulushini 2 ni chiqarib, bekor qilish hisobiga eng past shartlarga kamaytiring.

$$\frac{20}{49}+\frac{1}{2}\times \frac{3}{7}$$

Suratni maxrajga va maxrajini suratga ko‘paytirish orqali \frac{1}{2} ni \frac{3}{7} ga ko‘paytiring.

$$\frac{20}{49}+\frac{1\times 3}{2\times 7}$$

\frac{1\times 3}{2\times 7} kasridagi ko‘paytirishlarni bajaring.

$$\frac{20}{49}+\frac{3}{14}$$

49 va 14 ning eng kichik umumiy karralisi 98 ga teng. \frac{20}{49} va \frac{3}{14} ni 98 maxraj bilan kasrlarga aylantirib oling.

$$\frac{40}{98}+\frac{21}{98}$$

\frac{40}{98} va \frac{21}{98} da bir xil maxraji bor, ularning suratini qo‘shish orqali qo‘shing.

$$\frac{40+21}{98}$$

61 olish uchun 40 va 21'ni qo'shing.

$$\frac{61}{98}$$

Omil

$$\frac{61}{2 \cdot 7 ^ {2}} = 0,6224489795918368$$