Câu 1: (2 điểm) Thực hiện phép tính sau: a) $\frac{9}{17}$ + $\frac{8}{9}$ : $\frac{17}{9}$ b) ($\frac{2}{3}$)² + |(-2$\frac{1}{3}$)| - $\sqrt{\frac{49}{64}}$ c) ($\frac{15}{11}$ - $\frac{4}{13}$) : $\frac{12}{17}$ + ($\frac{7}{11}$ - $\frac{9}{13}$) : $\frac{12}{17}$ d) $\frac{20³.(-49)²}{14³.5^{4}}$

a) $\frac{9}{17}$ + $\frac{8}{9}$ ÷ $\frac{17}{9}$ 

= $\frac{9}{17}$ + $\frac{8}{9}$ × $\frac{9}{17}$ 

= $\frac{9}{17}$ + $\frac{8}{17}$ 

= 1

b) ($\frac{2}{3}$)² + |(-2$\frac{1}{3}$)| -$\sqrt[]{\frac{49}{64} }$

= $\frac{4}{9}$ + $\frac{7}{3}$ - $\frac{7}{8}$  

= $\frac{32}{72}$ + $\frac{168}{72}$ - $\frac{63}{72}$ 

= $\frac{137}{72}$ 

c) ($\frac{15}{11}$ - $\frac{4}{13}$) ÷ $\frac{12}{17}$ + ($\frac{7}{11}$ - $\frac{9}{13}$) ÷ $\frac{17}{12}$

= [($\frac{15}{11}$ - $\frac{4}{13}$) + ($\frac{7}{11}$ - $\frac{9}{13}$)] ÷ $\frac{12}{17}$

= 1 ÷ $\frac{12}{17}$

= $\frac{17}{12}$

d) $\frac{20² × (-49)²}{14³ × $5^{4}$ }$

= $\frac{8000 × 2401}{2744 × 625}$

= $\frac{56}{5}$