Câu hỏi của Enzo_135

Question

Tính

a,√99 :√11

b,√7,84

c,√1815 :√15

Bùi Thế Vinh · Accepted Answer

a) $\sqrt{99} : \sqrt{11}$

$$= \sqrt{\frac{99}{11}} = \sqrt{9} = 3$$

b) $\sqrt{7{,}84}$

$$= \sqrt{\frac{784}{100}} = \frac{\sqrt{784}}{\sqrt{100}} = \frac{28}{10} = 2{,}8$$

c) $\sqrt{1815} : \sqrt{15}$

$$= \sqrt{\frac{1815}{15}} = \sqrt{121} = 11$$Câu trả lời:

a) $\sqrt{99} : \sqrt{11}$

$$= \sqrt{\frac{99}{11}} = \sqrt{9} = 3$$

b) $\sqrt{7{,}84}$

$$= \sqrt{\frac{784}{100}} = \frac{\sqrt{784}}{\sqrt{100}} = \frac{28}{10} = 2{,}8$$

c) $\sqrt{1815} : \sqrt{15}$

$$= \sqrt{\frac{1815}{15}} = \sqrt{121} = 11$$