(42+20):4-2*(9:3)-2*[18+3*(13-9)-5]= eching

$$( 42 + 20 ) : 4 - 2 \cdot ( 9 : 3 ) - 2 \cdot [ 18 + 3 \cdot ( 13 - 9 ) - 5 ] =$$

Baholash

$$-\frac{81}{2}=-40,5$$

Yechim qadamlari

62 olish uchun 42 va 20'ni qo'shing.

$$\frac{62}{4}-2\times \frac{9}{3}-2\left(18+3\left(13-9\right)-5\right)$$

\frac{62}{4} ulushini 2 ni chiqarib, bekor qilish hisobiga eng past shartlarga kamaytiring.

$$\frac{31}{2}-2\times \frac{9}{3}-2\left(18+3\left(13-9\right)-5\right)$$

3 ni olish uchun 9 ni 3 ga bo‘ling.

$$\frac{31}{2}-2\times 3-2\left(18+3\left(13-9\right)-5\right)$$

6 hosil qilish uchun 2 va 3 ni ko'paytirish.

$$\frac{31}{2}-6-2\left(18+3\left(13-9\right)-5\right)$$

6 ni \frac{12}{2} kasrga o‘giring.

$$\frac{31}{2}-\frac{12}{2}-2\left(18+3\left(13-9\right)-5\right)$$

\frac{31}{2} va \frac{12}{2} da bir xil maxraji bor, ularning suratini ayirish orqali ayiring.

$$\frac{31-12}{2}-2\left(18+3\left(13-9\right)-5\right)$$

19 olish uchun 31 dan 12 ni ayirish.

$$\frac{19}{2}-2\left(18+3\left(13-9\right)-5\right)$$

4 olish uchun 13 dan 9 ni ayirish.

$$\frac{19}{2}-2\left(18+3\times 4-5\right)$$

12 hosil qilish uchun 3 va 4 ni ko'paytirish.

$$\frac{19}{2}-2\left(18+12-5\right)$$

30 olish uchun 18 va 12'ni qo'shing.

$$\frac{19}{2}-2\left(30-5\right)$$

25 olish uchun 30 dan 5 ni ayirish.

$$\frac{19}{2}-2\times 25$$

50 hosil qilish uchun 2 va 25 ni ko'paytirish.

$$\frac{19}{2}-50$$

50 ni \frac{100}{2} kasrga o‘giring.

$$\frac{19}{2}-\frac{100}{2}$$

\frac{19}{2} va \frac{100}{2} da bir xil maxraji bor, ularning suratini ayirish orqali ayiring.

$$\frac{19-100}{2}$$

-81 olish uchun 19 dan 100 ni ayirish.

$$-\frac{81}{2}$$

Omil

$$-\frac{81}{2} = -40\frac{1}{2} = -40,5$$