n: =345:(-345)=-1

sao bạn ko làm 2 cau trên ??

\(27.77+24.27-27\)

\(=27.\left(77+24-1\right)\)

\(=27.100\)

\(=2700\)

\(174\div\left\{2\left[36+\left(4^2-23\right)\right]\right\}\)

\(=174\div\left\{2\left[36+\left(16-23\right)\right]\right\}\)

\(=174\div\left\{2\left[36+\left(-7\right)\right]\right\}\)

\(=174\div\left\{2.29\right\}\)

\(=174\div58\)

\(=3\)

\(3^2.4-\left[30-\left(5-2\right)^2\right]\)

\(=9.4-\left[30-3^2\right]\)

\(=36-\left[30-9\right]\)

\(=36-21\)

\(=15\)

a) 100 - (3 - 3⁵ - 3 . 3³)

= 100 - (3 - 243 - 3 . 27)

= 100 - (3 - 243 - 81)

= 100 - (-321)

= 421

b) 27 . 76 + 24 . 27 + 260

= 27 . (76 + 24) + 260

= 27 . 100 + 260

= 2700 + 260

= 2960

`a,`

`31/23-(7/32+8/23)`

`=31/23-7/32-8/23`

`=(31/23-8/23)-7/32`

`=1-7/32=25/32`

`b,`

`38/45-(8/45-17/51-3/11)`

`=38/45-8/45+17/51+3/11`

`= (38/45-8/45)+17/51+3/11`

`=2/3+17/51+3/11`

`=1+3/11=14/11`

`c,`

`(1/3+12/67+13/41)-(79/67-28/41)`

`= 1/3+12/67+13/41-79/67+28/41`

`= 1/3+(12/67-79/67)+(13/41+28/41)`

`= 1/3+(-1)+1=1/3+(-1+1)=1/3+0=1/3`

`d,`

`1/5+(-1/6)+1/7+(-1/8)+1/9+1/8+(-1/7)+1/6+(-1/5)`

`= (1/5+ -1/5)+(-1/6+1/6)+(1/7+ -1/7)+(-1/8 +1/8)+1/9`

`= 0+0+0+0+1/9=1/9 .`

a) 80- (4.52 - 3.23)

= 80- ( 208 -69 )

=80+139  quy tắc đổi dấu trừ tước dấu ngoặc

= 219

e: Ta có: \(2448:\left[119-\left(23-6\right)\right]\)

\(=2448:\left(119-23+6\right)\)

\(=2448:102=24\)

a: =-11/23(6/7+8/7)-1/23

=-22/23-1/23

=-1

b: =21/23-21/23+125/143-125/143

=0

A

a

b) 36 : 3 2 + 3 2 . 2 3  -150

= 36 : 9 + 9 . 8 – 1 = 4 + 72 – 1 = 76 – 1 = 75

Hình như đề hơi sai, t sửa lại đề nhé :)

\(\frac{24.47-23}{24+23.47}\)

\(=\frac{\left(23+1\right)47-23}{24+23.47}=\frac{47.23+47-23}{24+23.47}=\frac{47.23+24}{24+23.47}=1\)

P/s: Hoq chắc :<