C. HOẠT ĐỘNG LUYỆN TẬPCâu 1: Trang 13 sách VNEN 9 tập 1Tính:a)$\sqrt{\frac{1,44}{3,61}}$...

{
"content1": "a) $\sqrt{\frac{1,44}{3,61}} = \sqrt{\frac{144}{361}} = \frac{12}{19}$",
"content2": "b) $\sqrt{\frac{0,25}{9}} = \sqrt{\frac{25}{900}} = \frac{5}{30} = \frac{1}{6}$",
"content3": "c) $\sqrt{1\frac{13}{36}.3\frac{13}{36}} = \sqrt{\frac{49}{36} \times \frac{109}{36}} = \sqrt{\frac{49 \times 109}{36 \times 36}} = \frac{7 \times 13}{6 \times 6} = \frac{91}{36}$",
"content4": "d) $\sqrt{\frac{1}{121}.3\frac{6}{25}} = \sqrt{\frac{3}{121} \times \frac{6}{25}} = \sqrt{\frac{18}{121 \times 25}} = \sqrt{\frac{18}{3025}} = \frac{3\sqrt{2}}{35}$",
"content5": "e) $\sqrt{1\frac{13}{36}.2\frac{2}{49}.2\frac{7}{9}} = \sqrt{\frac{49}{36} \times \frac{2}{49} \times \frac{56}{9}} = \sqrt{\frac{98}{36} \times \frac{56}{9}} = \sqrt{\frac{7 \times 14}{3} \times \frac{8 \times 7}{3}} = \sqrt{\frac{98 \times 56}{36 \times 9}} = \sqrt{\frac{5488}{324}} = \frac{74}{9}$",
"content6": "g) $\sqrt{\frac{165^{2}-124^{2}}{164}} = \sqrt{\frac{27***6}{164}} = \sqrt{\frac{11849}{164}} = \sqrt{72,33} \approx 8,5"
}