a) \(35\left(14-101\right)-14\left(35-10\right)\)

\(=35\cdot14-35\cdot101-14\cdot35+14\cdot10\)

\(=140-3535=-3395\)

b) \(5^2\cdot\left(-3\right)^3=25\cdot\left(-27\right)=-675\)

a,  35. ( 14 - 101 ) -  14 . ( 35 - 10 )
= 35 . 14 - 35 . 101 - 14 . 35 + 14 . 10

= 35 . 14 . ( - 35 . 101 - 14 . 10 )

= 490 . ( - 3535 - 140) 

= 490 . ( - 35675 ) 

~~ Tự tính nốt nhé

b, \(5^2.\left(-3\right)^3=25.\left(-27\right)\)= - 675

@@ Học tốt

Sai đề k??

a)5*2^2-18:3=20-6=14

b)17*85+15*17-120=17*(120-85+15)=17*20=340

c2^3*17-2^3*14=2^3(17-14)=8*3=24

a: =17x100-120=1700-120=1580

a) \(17\cdot85+15\cdot17-120\)
\(=17\cdot\left(85+15\right)-120\)
\(=17\cdot100-120\)
\(=1700-120\)
\(=1580\)
b) \(27\cdot77+24\cdot27-27\)
\(=27\cdot\left(77+24-1\right)\)
\(=27\cdot100\)
\(=2700\)

Bài 2:

Ta thấy: 5² > 4.5

6² > 5.6

7² > 6.7

     ....

2017² > 2016.2017

\(\Rightarrow\)\(\frac{1}{5^2}< \frac{1}{4.5}\)

\(\frac{1}{6^2}< \frac{1}{5.6}\)

\(\frac{1}{7^2}< \frac{1}{6.7}\)

....

\(\frac{1}{2017^2}< \frac{1}{2016.2017}\)

Cộng vế với nhau, ta có:

\(\frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{2017^2}\) < \(\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+...+\frac{1}{2016.2017}\)

\(\Rightarrow\)A < \(\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+...+\frac{1}{2016}-\frac{1}{2017}\)

\(\Rightarrow\)A < \(\frac{1}{4}-\frac{1}{2017}\)

\(\Rightarrow\)A < \(\frac{1}{4}\)( vì \(\frac{1}{2017}>0\))

k giúp mik ✅

Bài 1:

- 2 2/15 .3/8 - (7/20 - 75%) : 8/5

= -32/15.3/8 - (7/20 - 3/4) x 5/8

= - 4/5 - (7/20 - 15/20) x 5/8

= - 4/5 + 8/20 x 5/8

= - 4/5 + 1/4

= - 16/20 + 5/20

= - 11/20

`a,5 xx (-7)+(-2) xx (-5)`

`=5 xx (-7)+5 xx 2`

`= 5 xx (2-7)`

`=5 xx (-5)`

`=-25`

`b,5 xx (-9)+(-2) xx 3`

`=3 xx (-15)+3 xx (-2)`

`=3 xx (-15-2)`

`=3 xx (-17)`

`=-51`

`c,6 xx (-5)^2+3 xx (-15)`

`=2 xx 3 xx 25+3 xx (-15)`

`=3 xx 75-3 xx 15`

`=3 xx (75-15)`

`=3 xx 60`

`=180`

a) 5×(-7) +(-2) ×(-5)

=5.(-7)+2.5

=5.(-7+2)

=5.(-5)=-25

a)=-7/21+8/24

=-1/3+1/3

=0

b)=-3/5.(2/7+5/7)+23/5

=-3/5.7/7+23/5

=-3/5.1+23/5

=-3/5+23/5

=20/5=4

c)=75/100-11/2+5/10:5/12+1/4

=3/4-11/2+1/2:5/12+1/4

=3/4+-11/2+1/2.12/5+1/4

=3/4+-22/4+6/5+1/4

=-19/4+6/5+1/4

=(-19/4+1/4)+6/5

=-18/4+6/5

=-9/2+6/5

=-45/10+12/10

=-23/10

Câu a:

7/10.4/9 + 3/10.4/9 - 1 7/9

= 4/9.(7/10 + 3/10) - 16/9

= 4/9 - 16/9

= - 12/9

= - 4/3

Câu b:

- 5/6 + 4/9.(5/4 - 2/3).(-3)^2 + 5/9.30%

= - 5/6 + [5/9 - 8/27].9 + 5/9.3/10

= - 5/6 + 5 - 8/3 + 1/6

= (-5/6 + 1/6) - 8/3 + 5

= - 4/6 - 8/3 + 15/3

= - 2/3 - 8/3 + 15/3

= - 10/3 + 15/3

= 5/3

Câu a:

A = 7 2/13 - (5 2/13 + 2 1/2)

A = 7 2/13 - 5 2/13 - 2 1/2

A = 2 - 2 1/2

A = 2 - 2 - 1/2

A = 0 - 1/2

A = -1/2

Câu b:

B = - 3/4 + 25% : (10 3/10 - 9 4/5) - (-1/2)^2

B = - 3/4 + 1/4 : (103/10 - 49/5) - 1/4

B = - 3/4 + 1/4 : (103/10 - 98/5) - 1/4

B = (-3/4 - 1/4) + 1/4 : (1/2)

B = -1 + 1/4 x 2/1

B = -1 + 1/2

B = - 1/2