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27 tháng 6 2016

A = \(\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)

\(=3,1-2,5+2,5-3,1=6,2\)

B = \(\left(5,3-2,8\right)-\left(4+5,3\right)\)

\(=5,3-2,8-4-5,3=-6,8\)

C = \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)

\(=-251.3-281+3.251-1+281=-1\)

D = \(-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)\)

\(=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)

(Nhớ k cho mình với nhá!)

5 tháng 9 2016

A= (3,1 - 2,5) - (-2,5 + 3,1)

=3.1-2.5+2.5-3.1

=0

B= (5,3 - 2,8) - (4 + 5,3)

=5.3 - 2.8-4-5.3

= -6.8

C= -(251.3 + 281) + 3.251 - (1-281)

=-251.3-281+3.251-1+281

=-1

D= -(3/5+3/4)(3/4+2/5)

= -3/5-3/4+3/4-2/5

= -5/5

=-1

5 tháng 9 2016

\(A=\left(3,1-2,5\right)-\left(-2,5+3,1\right)=3,1-2,5+2,5-3,1=0\)

\(B=\left(5,3-2,8\right)-\left(4+5,3\right)=5,3-2,8-4-5,3=-6,8\)

\(C=-\left(215\cdot3+281\right)+3\cdot215-\left(1-281\right)=-215\cdot3-281+3\cdot215-1+281=1\)

\(D=-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)

10 tháng 6 2017

\(A=\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)

\(A=3,1-2,5+2,5-3,1\)

\(A=\left(3,1-3,1\right)-\left(2,5-2,5\right)\)

\(A=0-0\)

\(A=0\)

10 tháng 6 2017

\(B=\left(5,3-2,8\right)-\left(4+5,3\right)\)

\(B=5,3-2,8-4-5,3\)

\(B=\left(5,3-5,3\right)-\left(2,8+4\right)\\ B=0-6,8\\ B=-6,8\)

15 tháng 9 2017

a) (4,1 - 2,5 ) - ( -2,5 + 3,1 ) = 1,6 - 0,6 = 1

b) ( 5,3 - 2,8) - ( 4+ 5,3) = 2,5 - 9,3 = -6.8

c) -( 251,3 + 281) + 3,251 - (1 - 981) = -532,3 + 3,251 + 980 = 450,951

d) -(3/5 + 3/4) - ( -3/4 +2/5) = -3/5 - 3/4 + 3/4 - 2/5 = -1

27 tháng 6 2017

1a, (-3,8) + [ (-5,7)+3,8]

= (-3,8+3,8) -5,7

= -5,7

b, 31,4 +[6,4 +(-18)]

= 31,4 - 11,6

= 19,8

c,[(9,6 )+4,5 ] +[9,6 +(-1,5)]

= 9,6 +9,6 +(4,5-1,5)

= 19,2 +3

=22,2

d, [ (-4,9) + (-7,8)] +[1,9+2,8]

= (-4,9 +1,9)+ (-7,8+2,8)

= -3 -5

=-8

e, (3,1-2,5)-(-2,5+3,1)

= (3,1-3,1)+(2,5-2,5)

=0

f, (5,3 -2,8 )- (4+5,3)

= (5,3-5,3) -2,8-4

= -6,8

g, -(251,3 +281 )+ 3,251 -(1-281)

= -251,3-281+3,251 -1+281

= (-281+281) -251,3 +3,251 -1

= -249,049

h,-(3/54+3/4)-(-3/4 +2/5)

= -3/54-3/4 +3/4 +2/5

=(-3/4+3/4) -3/54 +2/5

=123/270

chúc bạn học tốt

27 tháng 6 2017

lấy mt bấm phắt là ra

HQ
Hà Quang Minh
Giáo viên
19 tháng 9 2023

a)

\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right).\\A = \left( {\frac{{30}}{{15}} + \frac{5}{{15}} - \frac{6}{{15}}} \right) - \left( {\frac{{105}}{{15}} - \frac{9}{{15}} - \frac{{20}}{{15}}} \right) - \left( {\frac{3}{{15}} + \frac{{25}}{{15}} - \frac{{60}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} - \left( {\frac{{ - 32}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} + \frac{{32}}{{15}}\\A = \frac{{ - 15}}{{15}}\\A =  - 1\end{array}\)

b)

\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right)\\A = 2 + \frac{1}{3} - \frac{2}{5} - 7 + \frac{3}{5} + \frac{4}{3} - \frac{1}{5} - \frac{5}{3} + 4\\A = \left( {2 - 7 + 4} \right) + \left( {\frac{1}{3} + \frac{4}{3} - \frac{5}{3}} \right) + \left( { - \frac{2}{5} + \frac{3}{5} - \frac{1}{5}} \right)\\A =  - 1 + 0 + 0 =  - 1\end{array}\)

HQ
Hà Quang Minh
Giáo viên
18 tháng 9 2023

\(\begin{array}{l}a)\left( {\frac{2}{3} + \frac{1}{6}} \right):\frac{5}{4} + \left( {\frac{1}{4} + \frac{3}{8}} \right):\frac{5}{2}\\ = \left( {\frac{4}{6} + \frac{1}{6}} \right).\frac{4}{5} + \left( {\frac{2}{8} + \frac{3}{8}} \right).\frac{2}{5}\\ = \frac{5}{6}.\frac{4}{5} + \frac{5}{8}.\frac{2}{5}\\ = \frac{2}{3} + \frac{1}{4}\\ = \frac{8}{{12}} + \frac{3}{{12}}\\ = \frac{{11}}{{12}}\\b)\frac{5}{9}:\left( {\frac{1}{{11}} - \frac{5}{{22}}} \right) + \frac{7}{4}.\left( {\frac{1}{{14}} - \frac{2}{7}} \right)\\ = \frac{5}{9}:\left( {\frac{2}{{22}} - \frac{5}{{22}}} \right) + \frac{7}{4}.\left( {\frac{1}{{14}} - \frac{4}{{14}}} \right)\\ = \frac{5}{9}:\frac{{ - 3}}{{22}} + \frac{7}{4}.\frac{{ - 3}}{{14}}\\ = \frac{5}{9}.\frac{{ - 22}}{3} + \frac{{ - 3}}{8}\\ = \frac{{ - 110}}{{27}} + \frac{{ - 3}}{8}\\ = \frac{{ - 880}}{{216}} + \frac{{ - 81}}{{216}}\\ = \frac{{ - 961}}{{216}}\end{array}\)

\(P=\left(\dfrac{-1}{2}-\dfrac{3}{5}\right):\left(-3\right)+\dfrac{1}{3}-\dfrac{1}{6}:2\)

\(=\left(\dfrac{1}{2}+\dfrac{3}{5}\right):3+\dfrac{1}{3}-\dfrac{1}{12}\)

\(=\dfrac{11}{10}\cdot\dfrac{1}{3}+\dfrac{1}{4}\)

\(=\dfrac{11}{30}+\dfrac{1}{4}=\dfrac{22}{60}+\dfrac{15}{60}=\dfrac{37}{60}\)

\(Q=\left(\dfrac{2}{25}-\dfrac{126}{125}\right)\cdot\dfrac{7}{4}:\left[\dfrac{-119}{36}\cdot\dfrac{36}{17}\right]\)

\(=\dfrac{-116}{125}\cdot\dfrac{7}{4}:\left(-7\right)\)

\(=\dfrac{116}{125}\cdot\dfrac{7}{4}\cdot\dfrac{1}{7}=\dfrac{29}{125}\)

16 tháng 7 2016

\(P=\left(-0,5-\frac{3}{5}\right):\left(-3\right)+\frac{1}{3}-\left(-\frac{1}{6}\right):\left(-2\right)\)

\(P=\left(-1,1\right):\left(-3\right)+\frac{1}{3}+\frac{1}{6}:\left(-2\right)\)

\(P=\frac{11}{30}+\frac{1}{3}+\left(-\frac{1}{12}\right)\)

\(P=\frac{37}{60}\)

\(Q=\left(\frac{2}{25}-1,008\right):\frac{4}{7}:\left[\left(3\frac{1}{4}-6\frac{5}{9}\right).2\frac{2}{17}\right]\)

\(Q=\left(-0,928\right):\frac{4}{7}:\left[\left(-\frac{119}{36}\right).2\frac{2}{17}\right]\)

\(Q=\left(-1,624\right):\left(-\frac{245}{36}\right)\)

\(Q=\frac{1044}{4375}\)