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

trả lời:

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

=13/60

1: =0,1-2,34=-2,24

2: =0,25+4,75-2,9=5-2,9=2,1

\(a,25.\left(7-27\right)+27.25\)

\(=25.7-27+27.25\)

\(=27.\left(25+25\right)-7\)

\(=27.50-7=135-7=128\)( ko chắc )

\(b,\left(-3\right)^2.\left(-2\right)^3\)

\(=9.\left(-8\right)=-72\)

thực hiện phép tính bằng cách hợp lí (nếu có thể)

a,136:{[(468+332):160-5]+68}+2014

= 136 : { [ ( 468 + 332 ) : 160 - 5 ] + 68 } + 2014

= 136 : { [ 800 : 160 - 5 ] + 68 } + 2014

= 136 : { [ 5 - 5 ] + 68 } + 2014

= 136 : { 0 + 68 } + 2014

= 136 : 68 + 2014

= 2 + 2014

= 2016 

\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)

\(=136:\left[\left(800:160-5\right)+68\right]+2014\)

\(=136:\left[\left(5-5\right)+68\right]+2014\)

\(=136:\left(0+68\right)+2014\)

\(=136:68+2014=2+2014\)

\(=2016\)

\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)

\(=136:\left\{\left[800:160-5\right]+68\right\}+2014\)

\(=136:\left\{\left[5-5\right]+68\right\}+2014\)

\(=136:\left\{0+68\right\}+2014\)

\(=136:68+2014\)

\(=2+2014\)

\(=2016\)

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

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

\(=\left(-\frac{2}{4}-\frac{3}{4}\right)+\left(\frac{10}{15}+\frac{12}{15}\right)\)

\(=\left(\frac{-2-3}{4}\right)+\left(\frac{10+12}{15}\right)\)

\(=\left(\frac{-5}{4}\right)+\left(\frac{22}{15}\right)\)

\(=\frac{-75}{60}+\frac{88}{60}\)

\(=\frac{-75+88}{60}\)

\(=\frac{13}{60}\)

Mình ghi rõ từng chi tiết rồi nha , chúc bạn học tốt !!! 

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

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

= -5/4 + 22/15

= 13/60

Thực hiện phép tính ( bằng cách hợp lí nếu có thể ) 

A. 2/3 - (- 1/4)+3/5-(+7/45)-(-5/9)+1/12+1/39 

B. 6.(-2/3)^2 - 3(-2/3)^2 - 2 : (-3/2)+4

a: \(=23\cdot100+300=2600\)

b: \(=300:\left(4+6\right)-25=30-25=5\)

a) 23.(16+84)+300=23.100+300=2600

b)300:(4+6)-25=300:10-25=5 

= 280 :  [25 + ( 30 - 3 mũ 3 ) ]

= 280 :  [ 25 + ( 30 - 27 ) ]

=  280 : ( 25 + 3 )

= 280 : 28

=10