25/4-r^2/9 eching

$$\frac { 25 } { 4 } - \frac { r ^ { 2 } } { 9 }$$

Baholash

$$-\frac{r^{2}}{9}+\frac{25}{4}$$

Qisqa yechim qadamlari

Ifodalarni qo‘shish yoki ayirish uchun ularni yoyib, maxrajlarini bir xil qiling. 4 va 9 ning eng kichik umumiy karralisi 36. \frac{25}{4} ni \frac{9}{9} marotabaga ko'paytirish. \frac{r^{2}}{9} ni \frac{4}{4} marotabaga ko'paytirish.

$$\frac{25\times 9}{36}-\frac{4r^{2}}{36}$$

\frac{25\times 9}{36} va \frac{4r^{2}}{36} da bir xil maxraji bor, ularning suratini ayirish orqali ayiring.

$$\frac{25\times 9-4r^{2}}{36}$$

25\times 9-4r^{2} ichidagi ko‘paytirishlarni bajaring.

$$\frac{225-4r^{2}}{36}$$

Omil

$$\frac{\left(-2r-15\right)\left(2r-15\right)}{36}$$

Yechim qadamlari

\frac{1}{36} omili.

$$\frac{225-4r^{2}}{36}$$

Hisoblang: 225-4r^{2}. 225-4r^{2} ni 15^{2}-\left(2r\right)^{2} sifatida qaytadan yozish. Kvadratlarning farqini ushbu formula bilan hisoblash mumkin: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).

$$\left(15-2r\right)\left(15+2r\right)$$

Shartlarni qayta saralash.

$$\left(-2r+15\right)\left(2r+15\right)$$

Toʻliq ajratilgan ifodani qaytadan yozing.

$$\frac{\left(-2r+15\right)\left(2r+15\right)}{36}$$