left(5+5+left(30-1right)dright)30/2=390 eching

$$\frac{ \left( 5+5+ \left( 30-1 \right) d \right) 30 }{ 2 } =390$$

d uchun yechish

$$d=\frac{16}{29}\approx 0,551724138$$

Chiziqli tenglamalarni yechish bo'yicha qadamlar

Ikkala tarafini 2 ga ko‘paytiring.

$$\left(5+5+\left(30-1\right)d\right)\times 30=390\times 2$$

10 olish uchun 5 va 5'ni qo'shing.

$$\left(10+\left(30-1\right)d\right)\times 30=390\times 2$$

29 olish uchun 30 dan 1 ni ayirish.

$$\left(10+29d\right)\times 30=390\times 2$$

10+29d ga 30 ni ko'paytirish orqali distributiv xususiyatdan foydalanish.

$$300+870d=390\times 2$$

780 hosil qilish uchun 390 va 2 ni ko'paytirish.

$$300+870d=780$$

Ikkala tarafdan 300 ni ayirish.

$$870d=780-300$$

480 olish uchun 780 dan 300 ni ayirish.

$$870d=480$$

Ikki tarafini 870 ga bo‘ling.

$$d=\frac{480}{870}$$

\frac{480}{870} ulushini 30 ni chiqarib, bekor qilish hisobiga eng past shartlarga kamaytiring.

$$d=\frac{16}{29}$$