BT1: Rút gọn
1) \(\frac{124.237+152}{870+235.122}\)
BT2: Tính:
1) \(\frac{377.733+722}{379.733-744}\) + 3. (-4)\(^3\) - 5 . (-2)\(^5\)
Tính nhanh :
a , ( 1374 : 57 + 687 : 86 ) : ( 26x13+74x14)
b , ( 124x237+152) : ( 870 + 235 x122)
Tính hợp lí :
a) ( 1374 . 57 + 687 . 86 ) . ( 26 . 13 + 74 . 14 )
b) ( 124 . 237 + 152 ) : ( 870 + 235 . 122 )
BT2: Tính nhanh
5) \(1-\dfrac{1}{2}+2-\dfrac{2}{3}+3-\dfrac{3}{4}+4-\dfrac{1}{4}-3-\dfrac{1}{3}-2-\dfrac{1}{2}-1\)
6) \(\left(\dfrac{5}{7}-\dfrac{7}{5}\right)-\left[\dfrac{1}{2}-\left(-\dfrac{2}{7}-\dfrac{1}{10}\right)\right]\)
BT2: Tính
3) -6\(^3\) + (\(\frac{137.454+206}{453.138-110}\)) . (4.2-3\(^2\).2)
BT2: Tính nhanh
9) (\(\left(5+\dfrac{1}{5}-\dfrac{2}{9}\right)-\left(2-\dfrac{1}{23}-2\dfrac{3}{35}+\dfrac{5}{6}\right)-\left(8+\dfrac{2}{7}-\dfrac{1}{18}\right)\)
10)\(\dfrac{1}{3}-\dfrac{3}{4}-\left(-\dfrac{3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\)
tính hợp lí ( nếu có thể )
\(\frac{1}{3}.\frac{-6}{13}.\frac{-9}{10}.\frac{-13}{36}\)
\(\frac{-1}{3}.\frac{-15}{17}.\frac{34}{45}\)
\(\left(1-\frac{1}{5}\right).\left(\frac{-3}{10}+\frac{1}{5}\right)\)
\(A=\frac{1}{3}\times\frac{4}{5}+\frac{1}{3}\times\frac{6}{5}+\frac{2}{3}\)
\(11\frac{1}{4}-\left(2\frac{5}{7}+5\frac{1}{4}\right)\)
vận dụng tính chất các phép tính để tìm các kết quả bằng cách nhanh chóng
a.1990 x 1990 - 1992 x 1998
b. ( 1374 x 57 + 687 x 86 ) : ( 26 x 13 + 74 x 14)
c. ( 124 x 237 + 152 ) : ( 870 + 235 x 122)
d.\(\frac{423134\cdot846267-423133}{846267\cdot423133\cdot423134}\)
