Question

Đã trả lời bởi chuyên gia

Answer 1

$a) \frac{7}{5} + \frac{18}{15} = \frac{7}{5} + \frac{18 : 3}{15 : 3} = \frac{7}{5} + \frac{6}{5} = \frac{13}{5} b) \frac{5}{4} + \frac{17}{12} = \frac{5 x 3}{12} + \frac{17}{12} = \frac{15 + 17}{12} = \frac{32}{12} = \frac{8}{3} c) \frac{1}{2} + \frac{1}{6} + \frac{2}{3} = \frac{3}{6} + \frac{1}{6} + \frac{4}{6} = \frac{8}{6} = \frac{4}{3}$

$d) 2 + \frac{1}{3} = \frac{6}{3} + \frac{1}{3} = \frac{7}{3}$

e) $\frac{25}{26} - \frac{15}{26} = \frac{25 - 15}{26} = \frac{10}{26} = \frac{5}{13}$

f) $\frac{46}{39} - \frac{11}{13} = \frac{46}{39} - \frac{11 x 3}{39} = \frac{46 - 33}{39} = \frac{13}{39} = \frac{1}{3}$

g) $\frac{37}{45} - \frac{5}{9} = \frac{37}{45} - \frac{25}{45} = \frac{12}{45}$ = $\frac{4}{5}$

x) $1 - \frac{1}{3} = \frac{3 - 1}{3} = \frac{2}{3}$

câu 2,

chu vi của hình chữ nhật đó là

$2 x (1 + \frac{7}{10}) = \frac{17}{5} (m) Đ S \frac{17}{5} m$

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Answer 2