Câu 2: trang 158 - toán tiếng anh lớp 5Calculate in the simplest way:Tính bằng cách thuận tiện...

{
"Câu 1": "a) (689 + 875) + 125 = 1564 + 125 = 1689 ; 581 + (878 + 419) = 581 + 1297 = 1878",
"Câu 2": "b) (\(\frac{2}{7}\) + \(\frac{4}{9}\)) + \(\frac{5}{7}\) = \(\frac{23}{63}\) + \(\frac{4}{9}\) + \(\frac{5}{7}\) = \(\frac{23}{63}\) + \(\frac{28}{63}\) = \(\frac{51}{63}\) = \(\frac{17}{21}\) ; \(\frac{17}{11}\) + (\(\frac{7}{15}\) + \(\frac{5}{11}\)) = \(\frac{17}{11}\) + \(\frac{92}{165}\) = \(\frac{170}{55}\) = \(\frac{34}{11}\)",
"Câu 3": "c) 5,87 + 28,69 + 4,13 = 38,69 + 4,13 = 42,82 ; 83,75 + 46,98 + 6,25 = 130,73 + 6,25 = 136,98"
}