2*90^circ+(n-2)*120^circ=(2n-4)*90^circ eching

$$2 \times 90 ^ { \circ } + ( n - 2 ) \times 120 ^ { \circ } = ( 2 n - 4 ) \times 90 ^ { \circ }$$

n uchun yechish

$$n=5$$

Chiziqli tenglamalarni yechish bo'yicha qadamlar

180 hosil qilish uchun 2 va 90 ni ko'paytirish.

$$180+\left(n-2\right)\times 120=\left(2n-4\right)\times 90$$

n-2 ga 120 ni ko'paytirish orqali distributiv xususiyatdan foydalanish.

$$180+120n-240=\left(2n-4\right)\times 90$$

-60 olish uchun 180 dan 240 ni ayirish.

$$-60+120n=\left(2n-4\right)\times 90$$

2n-4 ga 90 ni ko'paytirish orqali distributiv xususiyatdan foydalanish.

$$-60+120n=180n-360$$

Ikkala tarafdan 180n ni ayirish.

$$-60+120n-180n=-360$$

-60n ni olish uchun 120n va -180n ni birlashtirish.

$$-60-60n=-360$$

60 ni ikki tarafga qo’shing.

$$-60n=-360+60$$

-300 olish uchun -360 va 60'ni qo'shing.

$$-60n=-300$$

Ikki tarafini -60 ga bo‘ling.

$$n=\frac{-300}{-60}$$

5 ni olish uchun -300 ni -60 ga bo‘ling.

$$n=5$$