Bài 1. Tính giá trị các biểu thức sau:
1) \(\dfrac{11}{24}\) - \(\dfrac{5}{41}\) - ( 0,5 - \(\dfrac{13}{24}\) + \(\dfrac{36}{41}\) )
2) \(\dfrac{11}{21}\) . \(\dfrac{5}{9}\) - \(\dfrac{11}{21}\) . \(\dfrac{2}{9}\) + \(\dfrac{1}{3}\) . \(\dfrac{10}{21}\)
3) \(\left|\dfrac{-5}{9}\right|\) + \(\left|\dfrac{16}{25}\right|\) - ( \(\dfrac{1}{3}\) )2
`1, 11/24 - 5/41 - (0,5 - 13/24 + 36/41)`
`= 11/24 - 5/41 - 0,5 + 13/24 - 36/41`
`= (11/24 + 13/24) + (-5/41 - 36/41) - 0,5`
`= 24/24 - 41/41 - 0,5`
`= 1 - 1 - 0,5`
`= 0 - 0,5`
`=-0,5`
`2, 11/21 . 5/9 - 11/21 . 2/9 + 1/3 . 10/21`
`= 11/21 . (5/9 - 2/9) + 1/3 . 10/21`
`= 11/21 , 1/3 + 1/3 . 10/21`
`= 1/3 . (11/21 + 10/21)`
`= 1/3 . 21/21`
`= 1/3 . 1 = 1/3`
`3, |(-5)/9| + |16/25| - (1/3)^2`
`= 5/9 + 16/25 - 1/9`
`= (5/9 - 1/9) + 16/25`
`= 4/9 + 16/25`
`= 244/225`
1,1124−541−(0,5−1324+3641)1,1124-541-(0,5-1324+3641)
=1124−541−0,5+1324−3641=1124-541-0,5+1324-3641
=(1124+1324)+(−541−3641)−0,5=(1124+1324)+(-541-3641)-0,5
=2424−4141− 0,5=2424-4141- 0,5
=1−1−0,5=1-1-0,5
=0−0,5=0-0,5
=-0,5
2,1121.59−1121.29+13.1021
=1121.(59−29)+13.1021
=1121,13
=13.(1121+1021)
=13.212
=13.1=1/3
3,∣∣∣−59∣∣∣+∣∣∣1625∣∣∣ −(13)23,|-5/9|+|16/25| -(13)2
=5/9+16/25−1/9
=(59−19)+16/25
=4/9+16/25
=244/225
