2p^2+9p-3=0 eching

$$2 p ^ { 2 } + 9 p - 3 = 0$$

p uchun yechish

$$p=\frac{\sqrt{105}-9}{4}\approx 0,311737691$$

$$p=\frac{-\sqrt{105}-9}{4}\approx -4,811737691$$

Kvadrat tenglamalaridan foydalanish qoidalari

ax^{2}+bx+c=0 shaklidagi barcha tenglamalarni kvadrat formulasi bilan yechish mumkin: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Kvadrat formula ikki yechmni taqdim qiladi, biri ± qo'shish bo'lganda, va ikkinchisi ayiruv bo'lganda.

$$2p^{2}+9p-3=0$$

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

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

9 kvadratini chiqarish.

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

-4 ni 2 marotabaga ko'paytirish.

$$p=\frac{-9±\sqrt{81-8\left(-3\right)}}{2\times 2}$$

-8 ni -3 marotabaga ko'paytirish.

$$p=\frac{-9±\sqrt{81+24}}{2\times 2}$$

81 ni 24 ga qo'shish.

$$p=\frac{-9±\sqrt{105}}{2\times 2}$$

2 ni 2 marotabaga ko'paytirish.

$$p=\frac{-9±\sqrt{105}}{4}$$

p=\frac{-9±\sqrt{105}}{4} tenglamasini yeching, bunda ± musbat. -9 ni \sqrt{105} ga qo'shish.

$$p=\frac{\sqrt{105}-9}{4}$$

p=\frac{-9±\sqrt{105}}{4} tenglamasini yeching, bunda ± manfiy. -9 dan \sqrt{105} ni ayirish.

$$p=\frac{-\sqrt{105}-9}{4}$$

Tenglama yechildi.

$$p=\frac{\sqrt{105}-9}{4} p=\frac{-\sqrt{105}-9}{4}$$

Kvadratni yakunlash bo'yicha qadamlar

Bu kabi kvadrat tenglamalarni kvadratni yakunlab yechish mumkin. Kvadratni yechish uchun tenglama avval ushbu shaklda bo'lishi shart: x^{2}+bx=c.

$$2p^{2}+9p-3=0$$

3 ni tenglamaning ikkala tarafiga qo'shish.

$$2p^{2}+9p-3-\left(-3\right)=-\left(-3\right)$$

O‘zidan -3 ayirilsa 0 qoladi.

$$2p^{2}+9p=-\left(-3\right)$$

0 dan -3 ni ayirish.

$$2p^{2}+9p=3$$

Ikki tarafini 2 ga bo‘ling.

$$\frac{2p^{2}+9p}{2}=\frac{3}{2}$$

2 ga bo'lish 2 ga ko'paytirishni bekor qiladi.

$$p^{2}+\frac{9}{2}p=\frac{3}{2}$$

\frac{9}{2} ni bo‘lish, x shartining koeffitsienti, 2 ga \frac{9}{4} olish uchun. Keyin, \frac{9}{4} ning kvadratini tenglamaning ikkala tarafiga qo‘shing. Ushbu qadam tenglamaning chap qismini mukammal kvadrat sifatida hosil qiladi.

$$p^{2}+\frac{9}{2}p+\left(\frac{9}{4}\right)^{2}=\frac{3}{2}+\left(\frac{9}{4}\right)^{2}$$

Kasrning ham suratini, ham maxrajini kvadratga ko'paytirib \frac{9}{4} kvadratini chiqarish.

$$p^{2}+\frac{9}{2}p+\frac{81}{16}=\frac{3}{2}+\frac{81}{16}$$

Umumiy maxrajni topib va hisoblovchini qo'shish orqali \frac{3}{2} ni \frac{81}{16} ga qo'shing. So'ngra agar imkoni bo'lsa kasrni eng kam shartga qisqartiring.

$$p^{2}+\frac{9}{2}p+\frac{81}{16}=\frac{105}{16}$$

p^{2}+\frac{9}{2}p+\frac{81}{16} omili. Odatda, x^{2}+bx+c mukammal kvadrat bo'lsa, u doimo \left(x+\frac{b}{2}\right)^{2} omil sifatida bo'lishi mumkin.

$$\left(p+\frac{9}{4}\right)^{2}=\frac{105}{16}$$

Tenglamaning ikkala tarafining kvadrat ildizini chiqarish.

$$\sqrt{\left(p+\frac{9}{4}\right)^{2}}=\sqrt{\frac{105}{16}}$$

Qisqartirish.

$$p+\frac{9}{4}=\frac{\sqrt{105}}{4} p+\frac{9}{4}=-\frac{\sqrt{105}}{4}$$

Tenglamaning ikkala tarafidan \frac{9}{4} ni ayirish.

$$p=\frac{\sqrt{105}-9}{4} p=\frac{-\sqrt{105}-9}{4}$$