3x^2=9x-5 eching

$$3 x ^ { 2 } = 9 x - 5$$

x uchun yechish

$$x=\frac{\sqrt{21}}{6}+\frac{3}{2}\approx 2,263762616$$

$$x=-\frac{\sqrt{21}}{6}+\frac{3}{2}\approx 0,736237384$$

Kvadrat tenglamalaridan foydalanish qoidalari

Ikkala tarafdan 9x ni ayirish.

$$3x^{2}-9x=-5$$

5 ni ikki tarafga qo’shing.

$$3x^{2}-9x+5=0$$

Ushbu tenglama standart shaklidadir: ax^{2}+bx+c=0. Kvadrat tenglama formulasida, \frac{-b±\sqrt{b^{2}-4ac}}{2a} 3 ni a, -9 ni b va 5 ni c bilan almashtiring.

$$x=\frac{-\left(-9\right)±\sqrt{\left(-9\right)^{2}-4\times 3\times 5}}{2\times 3}$$

-9 kvadratini chiqarish.

$$x=\frac{-\left(-9\right)±\sqrt{81-4\times 3\times 5}}{2\times 3}$$

-4 ni 3 marotabaga ko'paytirish.

$$x=\frac{-\left(-9\right)±\sqrt{81-12\times 5}}{2\times 3}$$

-12 ni 5 marotabaga ko'paytirish.

$$x=\frac{-\left(-9\right)±\sqrt{81-60}}{2\times 3}$$

81 ni -60 ga qo'shish.

$$x=\frac{-\left(-9\right)±\sqrt{21}}{2\times 3}$$

-9 ning teskarisi 9 ga teng.

$$x=\frac{9±\sqrt{21}}{2\times 3}$$

2 ni 3 marotabaga ko'paytirish.

$$x=\frac{9±\sqrt{21}}{6}$$

x=\frac{9±\sqrt{21}}{6} tenglamasini yeching, bunda ± musbat. 9 ni \sqrt{21} ga qo'shish.

$$x=\frac{\sqrt{21}+9}{6}$$

9+\sqrt{21} ni 6 ga bo'lish.

$$x=\frac{\sqrt{21}}{6}+\frac{3}{2}$$

x=\frac{9±\sqrt{21}}{6} tenglamasini yeching, bunda ± manfiy. 9 dan \sqrt{21} ni ayirish.

$$x=\frac{9-\sqrt{21}}{6}$$

9-\sqrt{21} ni 6 ga bo'lish.

$$x=-\frac{\sqrt{21}}{6}+\frac{3}{2}$$

Tenglama yechildi.

$$x=\frac{\sqrt{21}}{6}+\frac{3}{2} x=-\frac{\sqrt{21}}{6}+\frac{3}{2}$$

Kvadratni yakunlash bo'yicha qadamlar

Ikkala tarafdan 9x ni ayirish.

$$3x^{2}-9x=-5$$

Ikki tarafini 3 ga bo‘ling.

$$\frac{3x^{2}-9x}{3}=-\frac{5}{3}$$

3 ga bo'lish 3 ga ko'paytirishni bekor qiladi.

$$x^{2}+\left(-\frac{9}{3}\right)x=-\frac{5}{3}$$

-9 ni 3 ga bo'lish.

$$x^{2}-3x=-\frac{5}{3}$$

-3 ni bo‘lish, x shartining koeffitsienti, 2 ga -\frac{3}{2} olish uchun. Keyin, -\frac{3}{2} ning kvadratini tenglamaning ikkala tarafiga qo‘shing. Ushbu qadam tenglamaning chap qismini mukammal kvadrat sifatida hosil qiladi.

$$x^{2}-3x+\left(-\frac{3}{2}\right)^{2}=-\frac{5}{3}+\left(-\frac{3}{2}\right)^{2}$$

Kasrning ham suratini, ham maxrajini kvadratga ko'paytirib -\frac{3}{2} kvadratini chiqarish.

$$x^{2}-3x+\frac{9}{4}=-\frac{5}{3}+\frac{9}{4}$$

Umumiy maxrajni topib va hisoblovchini qo'shish orqali -\frac{5}{3} ni \frac{9}{4} ga qo'shing. So'ngra agar imkoni bo'lsa kasrni eng kam shartga qisqartiring.

$$x^{2}-3x+\frac{9}{4}=\frac{7}{12}$$

x^{2}-3x+\frac{9}{4} omili. Odatda, x^{2}+bx+c mukammal kvadrat bo'lsa, u doimo \left(x+\frac{b}{2}\right)^{2} omil sifatida bo'lishi mumkin.

$$\left(x-\frac{3}{2}\right)^{2}=\frac{7}{12}$$

Tenglamaning ikkala tarafining kvadrat ildizini chiqarish.

$$\sqrt{\left(x-\frac{3}{2}\right)^{2}}=\sqrt{\frac{7}{12}}$$

Qisqartirish.

$$x-\frac{3}{2}=\frac{\sqrt{21}}{6} x-\frac{3}{2}=-\frac{\sqrt{21}}{6}$$

\frac{3}{2} ni tenglamaning ikkala tarafiga qo'shish.

$$x=\frac{\sqrt{21}}{6}+\frac{3}{2} x=-\frac{\sqrt{21}}{6}+\frac{3}{2}$$