bạn phá ngoặc rồi tính nhé VD:(3/4+2/5)+3/5=3/4+2/5+3/5=3/4+5/5=3/4+1=7/4

1) 

(-1/4 + 5/8 ) + 2/3 

=3/8 + 2/3

=25/24

2)

(1/-4 + 5/ 8 ) + -3/8

=1/-4 + 5/8 + -3/8

=1/-4 + 2/8

= -2/8 + 2/8

=0 

k cho mk nha!!!!!!!!!!!!!!!

1, ( - 1/4 + 5/8 ) + -2/3

= -1/4 + 5/8 + -2/3

= -2/8 + 5/8 + -2/3

= 3/8 + -2/3

= 9/24 + -16/24

= 7/24

2, ( -1/4 + 5/8 ) + -3/8

= -1/4 + 5/8 + -3/8

= -2/8 + 5/8 + -3/8

= 3/8 + -3/8

= o

Trả lời :

\(10-\frac{3}{8}\times\frac{1}{5}-\frac{3}{8}\times\frac{4}{5}\)

\(=10-\left(\frac{3}{8}\times\frac{1}{5}+\frac{3}{8}\times\frac{4}{5}\right)\)

\(=10-\frac{3}{8}\)

\(=\frac{77}{8}\)

10 -3/8 x 1/5 -3/8 x 4/5

=10-3/8x (1/5-4/5)

=10 - 3/8 x (-3/5)

=10 - (-9/40)

=10 + 9/40 

=40/40 + 9/40

=49/40

chúc bn học tốt

1)     \(\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\left(\frac{4}{5}-\frac{3}{17}+\frac{1}{15}\right)\)

\(=\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\frac{4}{5}-\frac{3}{17}+\frac{1}{15}\)

\(=\left(\frac{1}{5}+\frac{4}{5}\right)+\left(\frac{3}{17}-\frac{3}{17}\right)-\left(\frac{4}{3}-\frac{1}{15}\right)\)

\(=1+0-\frac{19}{15}\)

\(=-\frac{14}{15}\)

MÌNH

NHẦM

CHÚT

NHA

KẾT QUẢ CUỐI CÙNG LÀ:

\(-\frac{4}{15}\)

sorry!!!

còn câu 2

=3/37/84

B = ( 7\(\frac{1}{3}\) + 8\(\frac{1}{5}\) ) - ( 7\(\frac{1}{5}\) + 8\(\frac{1}{7}\) - 3\(\frac{1}{4}\) )

B =  ( \(\frac{22}{3}\) + \(\frac{41}{5}\)) - ( \(\frac{36}{5}\) + \(\frac{57}{7}\) - \(\frac{13}{4}\) )

B =           \(\frac{233}{15}\)       -            \(\frac{1693}{140}\)

B =                    \(\frac{289}{84}\)

B=289/84

2.9 . 3/-11 + 2/9 . -8/11 + 1/3

= 2/9 . (3/-11 + -8/11) + 1/3

= 2/9 . (-1) + 1/3

= -2/9 + 1/3

= 1/9

3/5 . 7/8 - 3/5 . -1/5

= 3/8 . (7/8 - 1/5)

= 3/8 . 43/40

= 129/320

\(\frac{2}{9}\) x \(\frac{3}{-11}\) +\(\frac{2}{9}\) x\(\frac{-8}{11}\) +\(\frac{1}{3}\)                                                                                                                                        =\(\frac{1}{9}\)                                                                                                                                                                                             \(\frac{3}{5}\) *\(\frac{7}{8}\) -\(\frac{3}{5}\)*\(\frac{-1}{5}\) =\(\frac{129}{200}\)

A=2/7+-3/8+11/7+1/3+1/7+5/-8

A=(2/7 + 1/7 + 11/7) + (-3/8 + 5/-8) + 1/3

A=2 + (-1) + 1/3

A=1 + 1/3

A=4/3

B=-3/8+12/25+5/-8+2/-5+13/25

B=(-3/8 + 5/-8) + (12/25 + 13/25) + 2/-5

B=-1 + 1 + 2/-5

B=-2/5

a. 

\(\left(1\frac{1}{4}+\frac{3}{5}\right):\left(-\frac{11}{12}\right)+\left(\frac{3}{8}-1\frac{2}{5}\right):\left(-\frac{11}{12}\right)\) 

\(=\left(\frac{5}{4}+\frac{3}{5}+\frac{3}{8}-\frac{7}{5}\right):\left(-\frac{11}{12}\right)\)  

\(=\left(\frac{13}{8}-\frac{4}{5}\right):\left(-\frac{11}{12}\right)\) 

\(=\frac{33}{40}:\left(-\frac{11}{12}\right)\) 

\(=\frac{33}{40}\cdot\left(-\frac{12}{11}\right)\) 

\(=\frac{-9}{10}\)  

b. 

\(\left(\frac{3}{8}-1\frac{2}{5}\right):\left(-\frac{11}{15}\right)+\left(1\frac{1}{4}+\frac{3}{5}\right):\left(-\frac{11}{15}\right)\) 

\(=\left(\frac{3}{8}-\frac{7}{5}+\frac{5}{4}+\frac{3}{5}\right):\left(-\frac{11}{15}\right)\)  

\(=\left(\frac{13}{8}-\frac{4}{5}\right):\left(-\frac{11}{15}\right)\) 

\(=\frac{33}{40}:\left(-\frac{11}{15}\right)\) 

\(=\frac{33}{40}\cdot\left(-\frac{15}{11}\right)\) 

\(=\frac{-9}{8}\)

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

=1+1+1=3

`2/5+6/9+3/4+3/5+1/3+2/8`

`=(2/5+3/5)+(6/9+1/3)+(3/4+2/8)`

`=5/5+(6/9+3/9)+(6/8+2/8)`

`=1+9/9+8/8=1+1+1=3`

2/5 + 6/9 + 3/4 + 3/5 + 1/3 + 2/8

= (2/5 + 3/5) + (6/9 + 1/3) + (3/4 + 2/8)

= 1 + 1 + 1

= 3