(-(3)/(31))+ (-(6)/(17)) +( 1)/(2) + (-(28)/(31)) + (-(11)/(17)) + (-(1)/(6))
-3/31+-6/17+1/25+-28/31+-11/31+-11/17+-1/5
-3/31-6/17- (-1/25) + (-28/31)+(-11/17)-1/5
=-3/31-6/17+1/25-28/31-11/17-1/5
=-1-1-4/25=-2-4/25=-54/25
B= - 3/31 + -6/17 + 1/25 + -28/31 + -11/17 + -1/5
chi tiết giúp nhaaaaaaaa
a) \(\dfrac{-3}{17}\left(\dfrac{2}{3}+\dfrac{3}{17}\right)\)
b) \(D=\dfrac{-3}{31}+\dfrac{-6}{17}+\dfrac{1}{25}+\dfrac{-28}{31}+\dfrac{-11}{17}+\dfrac{-1}{5}\)
b: D=(-3/31-28/31)+(-6/17-11/17)+(1/25-5/25)
=-2-4/25=-54/25
\(\dfrac{-3}{31}\) +\(\dfrac{-6}{17}\)+\(\dfrac{1}{25}\)+\(\dfrac{-28}{31}\)+\(\dfrac{-11}{17}\)+\(\dfrac{-1}{5}\)
\(=\left[\left(-\dfrac{3}{31}\right)+\left(-\dfrac{28}{31}\right)\right]+\left[\left(-\dfrac{6}{17}\right)+\left(-\dfrac{11}{17}\right)\right]+\left[\dfrac{1}{25}+\left(-\dfrac{1}{5}\right)\right]\)
\(=\left(-1\right)+\left(-1\right)+\left[\dfrac{1}{25}+\left(-\dfrac{5}{25}\right)\right]\)
\(=\left(-1\right)+\left(-1\right)+\left(-\dfrac{4}{25}\right)\)
\(=\left(-2\right)+\left(-\dfrac{4}{25}\right)\)
\(=\left(-\dfrac{50}{25}\right)+\left(-\dfrac{4}{25}\right)\)
\(=-\dfrac{54}{25}\)
\(=\left(\dfrac{-3}{31}+\dfrac{-28}{31}\right)+\left(\dfrac{-6}{17}+\dfrac{-11}{17}\right)+\left(\dfrac{1}{25}+\dfrac{1}{5}\right)\)
\(=-1+-1+\left(\dfrac{1}{25}+\dfrac{-5}{25}\right)\)
\(=-2\)\(+\dfrac{-4}{25}\)
\(=\)\(\dfrac{50}{25}+\dfrac{-4}{25}\)
=\(\dfrac{46}{25}\)
Bài 1 tính bằng cách hợp lý a, -5/7+3/4+-1/5+-2/7+1/4 b, -3/31+-6/17+1/29+-28/31+-11/17+-1/5
a: \(=\dfrac{-5}{7}-\dfrac{2}{7}+\dfrac{3}{4}+\dfrac{1}{4}-\dfrac{1}{5}=-\dfrac{1}{5}\)
b: \(=\dfrac{-3}{31}-\dfrac{28}{31}+\dfrac{-6}{17}-\dfrac{11}{17}+\dfrac{1}{29}-\dfrac{1}{5}=\dfrac{-24}{145}\)
Bài 1:Tính:
a,3 14/19 + 13/17 + 35/43 + 6 5/19 + 8/13
b,130 25/28 + 120 17/35
c,17 2/31 - (15/17 + 6 2/31)
d,(31 6/13 + 5 9/41) - 31 6/13
e,(17 24/31 - 3 7/8) - (2 38/31 - 4)
g,1/1.2 + 1/2.3 + 1/3.4 + 1/4.5 + 1/5.6
h,1/1.2 + 1/2.3 + 1/3.4 + .........+ 1/49.100
i,1/1.3 + 1/3.5 + 1/5.7 +........+ 1/97.99
1) Tính nhanh
A= 4/7 + 3/4 + 2/7 + 5/4 + 1/7
B= -3/31 + -6/17 + 1/25 + -28/31 + -11/7 + -1/5
Mik cần nhanh, mai mik hok r T^T
1) Tính nhanh
\(A=\frac{4}{7}+\frac{3}{4}+\frac{2}{7}+\frac{5}{4}+\frac{1}{7}\)
\(=\left(\frac{4}{7}+\frac{2}{7}+\frac{1}{7}\right)+\left(\frac{3}{4}+\frac{5}{4}\right)\)
\(=1+2=3\)
Ghép tương tự vs B
A = \(\frac{4}{7}+\frac{3}{4}+\frac{2}{7}+\frac{5}{4}+\frac{1}{7}\)
= \(\left(\frac{2}{7}+\frac{4}{7}+\frac{1}{7}\right)+\left(\frac{3}{4}+\frac{5}{4}\right)\)
= \(1+2\)
= \(3\)
Dùng tính chất để tính
a) 17/5 . -31/125 . 1/2 . 10/17 . -1/23
b) (11/4 . -5/9 - 4/9 . 11/4) . 8/33
c) (17/28 + 18/29 - 19/30 - 20/31) . (-5/12 + 1/4 + 1/6)
d) -1/4 . 15^2/11 + 68/4 . -1/11
e) -9/25 . 53/3 - (-3/5)^2 .22/3