3: \(C=\left(\sqrt{\dfrac{16}{9}}+1\right)^2-\left(\sqrt{\dfrac{25}{16}}-\dfrac{1}{4}\right)^{100}+\dfrac{1}{3}:\dfrac{3}{5}\)\(=\left(\dfrac{4}{3}+1\right)^2-\left(\dfrac{5}{4}-\dfrac{1}{4}\right)^{100}+\dfrac{1}{3}\cdot\dfrac{5}{3}\)\(=\dfrac{49}{9}-1+\dfrac{5}{9}=\dfrac{54}{9}-1=6-1=5\)Bài 2:1: \(A=\left(-2\dfrac{1}{5}+\dfrac{2}{7}-\dfrac{12}{13}\right)-\left(-\dfrac{5}{7}+\dfrac{1}{13}\right)\)\(=-2-\dfrac{1}{5}+\dfrac{2}{7}-\dfrac{12}{13}+\dfrac{5}{7}-\dfrac{1}{13}\)\(=-\dfrac{11}{5}+\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\left(-\dfrac{12}{13}-\dfrac{1}{13}\right)\)\(=-\dfrac{11}{5}\)2: Sửa đề: \(B=\dfrac{12}{17}\cdot\dfrac{5}{7}-\dfrac{-12}{17}\cdot\dfrac{1}{7}+12\cdot\dfrac{1}{17\cdot7}\)\(=\dfrac{12}{17}\cdot\dfrac{5}{7}+\dfrac{12}{17}\cdot\dfrac{1}{7}+\dfrac{12}{17}\cdot\dfrac{1}{7}\)\(=\dfrac{12}{17}\left(\dfrac{5}{7}+\dfrac{1}{7}+\dfrac{1}{7}\right)=\dfrac{12}{17}\)3: \(C=\left(\dfrac{1}{3}-2\dfrac{1}{6}\right)^2:\left(-3\dfrac{13}{36}\right)\)\(=\left(\dfrac{2}{6}-\dfrac{13}{6}\right)^2:\left(-3\dfrac{13}{36}\right)\)\(=-\left(\dfrac{11}{6}\right)^2:\left(3+\dfrac{13}{36}\right)\)\(=-\dfrac{121}{36}:\dfrac{121}{36}=-1\)Câu trả lời: 3: \(C=\left(\sqrt{\dfrac{16}{9}}+1\right)^2-\left(\sqrt{\dfrac{25}{16}}-\dfrac{1}{4}\right)^{100}+\dfrac{1}{3}:\dfrac{3}{5}\)\(=\left(\dfrac{4}{3}+1\right)^2-\left(\dfrac{5}{4}-\dfrac{1}{4}\right)^{100}+\dfrac{1}{3}\cdot\dfrac{5}{3}\)\(=\dfrac{49}{9}-1+\dfrac{5}{9}=\dfrac{54}{9}-1=6-1=5\)Bài 2:1: \(A=\left(-2\dfrac{1}{5}+\dfrac{2}{7}-\dfrac{12}{13}\right)-\left(-\dfrac{5}{7}+\dfrac{1}{13}\right)\)\(=-2-\dfrac{1}{5}+\dfrac{2}{7}-\dfrac{12}{13}+\dfrac{5}{7}-\dfrac{1}{13}\)\(=-\dfrac{11}{5}+\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\left(-\dfrac{12}{13}-\dfrac{1}{13}\right)\)\(=-\dfrac{11}{5}\)2: Sửa đề: \(B=\dfrac{12}{17}\cdot\dfrac{5}{7}-\dfrac{-12}{17}\cdot\dfrac{1}{7}+12\cdot\dfrac{1}{17\cdot7}\)\(=\dfrac{12}{17}\cdot\dfrac{5}{7}+\dfrac{12}{17}\cdot\dfrac{1}{7}+\dfrac{12}{17}\cdot\dfrac{1}{7}\)\(=\dfrac{12}{17}\left(\dfrac{5}{7}+\dfrac{1}{7}+\dfrac{1}{7}\right)=\dfrac{12}{17}\)3: \(C=\left(\dfrac{1}{3}-2\dfrac{1}{6}\right)^2:\left(-3\dfrac{13}{36}\right)\)\(=\left(\dfrac{2}{6}-\dfrac{13}{6}\right)^2:\left(-3\dfrac{13}{36}\right)\)\(=-\left(\dfrac{11}{6}\right)^2:\left(3+\dfrac{13}{36}\right)\)\(=-\dfrac{121}{36}:\dfrac{121}{36}=-1\)