(35 - 17) - (-17 + 20 + 35)

=35-17+17-20-35

=35-35-17+17-20

=-20

\(\left(35-17\right)-\left(-17+20+35\right)\\ =18-\left(3+35\right)\\ =18-38\\ =-20\)

(35-17)-(-17+20+35)

=35-17+17-20-35

=(35-35)+[(-17)+17] -20

=-20

1;  (-8537 ) + ( 1975 + 8537)

=   - 8537   + 1975 + 8537

=  (-8537    +  8537) + 1975

= 0 + 1975

= 1975

2; ( 35 - 17 ) - ( -17 + 20 + 35)

= 35 - 17 + 17 - 20 - 35

= ( 35 - 35) + ( -17 + 17) - 20

= 0 + 0 - 20

= - 20 

`a) 465 + [ 58 + ( -465 ) + ( -38 ) ]`

`= 465 + 58 - 465 -38`

`= (465-465) + (58-38)`

`=0+ 20`

`=20`

`b) ( 35 - 17 ) + ( 17 + 20 - 35 )`

`= 35 -17 +17 +20-35`

`= (35-35) + (-17+17)+20`

`= 0 + 0 +20`

`=20`

$a)465+[58+(-465)+(-38)]$

=465+58−465−38$=465+58-465-38$

=(465−465)+(58−38)$=(465-465)+(58-38)$

=0+20$=0+20$

=20$=20$

�)(35−17)+(17+20−35)$b)(35-17)+(17+20-35)$

=35−17+17+20−35$=35-17+17+20-35$

=(35−35)+(−17+17)+20$=(35-35)+(-17+17)+20$

=0+0+20$=0+0+20$

=20$=20$

(35-17)+(17+20-35)

=35-17+17+20-35

=(35-35)+(-17+17)+20

=0+0+20

=20

mk nhầm , là 20 nhé 

=35-35+17-17+20=20

ĐS: 20

(35 - 17) + (17 + 20 - 35)

= 18 + 2

= 20

a) 35- {12 - [(-14)+(-2)] }
=35 - [12-(-14-2)]
=35-[12-16]
=35-(-4)
=35+4
=39
b) 49 - (- 54) - 23
=49 + 54 - 23
= 80

c) |31 - 17 | - |13 - 52|
= |14| - | -39|
=14-39
= -25
d) -|-5|+ (-19) + 18 +|11-4| - 57
=-5 - 19 + 18 + 7 - 57
= -5-1-50
=-56
e) 126 + (-20) + |124| - (- 320) - |- 150|
= 126 - 20 + 124 + 320 - 150
= 400

g) (- 17) + 5 +8 +17 + (-3)
=(-17+17)+(5+8-3)=10

h) [( -15) + ( - 21 )] - ( 25 -15 - 35- 21)
=-15-21-25+15+35+21
=(-15+15)+(21-21)+(35+15-25)
=25

a)

\(\left(-8537\right)+\left(1975+8537\right)\)

\(=\left(-8537\right)+1975+8537\)

\(=1975\)

b)

\(\left(35-17\right)+\left(17+20-35\right)\)

\(=35-17+17+20-35\)

\(=20\)

c)

\(273+\left[-34+27+\left(-273\right)\right]\)

\(=273-34+27-273\)

\(=27-34\)

\(=-7\)

a: =>2x+17=27

=>2x=27-17=10

=>x=5

b: =>2(19-x)=24

=>19-x=12

=>x=7

\(2\cdot x+17=3^5:3^2\)

\(\Rightarrow2\cdot x+17=3^3\)

\(\Rightarrow2\cdot x+17=27\)

\(\Rightarrow2\cdot x=27-17\)

\(\Rightarrow2\cdot x=10\)

\(\Rightarrow x=\dfrac{10}{2}\)

\(\Rightarrow x=5\)

___________

\(\left(19-x\right)\cdot2-20=4\)

\(\Rightarrow\left(19-x\right)\cdot2=24\)

\(\Rightarrow19-x=24:2\)

\(\Rightarrow19-x=12\)

\(\Rightarrow x=19-12\)

\(\Rightarrow x=7\)