Theo quy tắc của dấu ngoặc,ta có:

516+320+357+5000+612-(516+320)-(5000+357+612)+(-420)+(-580)

= 516+320+357+5000+612-516-320-5000-357-612+(-420)+(-580)

= (516-516)+(320-320)+(357-357)+(5000-5000)+(612-612)+(-420)+(-580)

= 0 + 0 + 0 + 0 + 0 + (-420)+(-580)

= 0 + 0 + 0 + 0 + (-420)+(-580)

= 0 + 0 + 0 + (-420)+(-580)

= 0 + 0 + (-420)+(-580)

= 0 + ((-420)+(-580))

= 0 + -1000

= -1000

\(=-5+325-\left[-308-612\right]\)

\(=320+920=1240\)

Quá easy

k giùm cái

Ta có : 

120 = 2³.3.5

320 = 2⁶.5

ƯCLN(120,320)=2³.5 = 4

Ta có :

168 = 2³.3.7

120 = 2³.3.5

144 = 2⁴.3²

ƯCLN(168,120,144)= 2³.3 = 24

Ta có : 

612 = 2².3².17

680 = 2³.5.17

ƯLCN(612,680)= 2².17 = 68

anh oi mac du e k dung 

nhung ma anh lam sai o phep dau y cai ket qua do

3987678×357+357×444+357×555+357

=357x(3987678+444+555+1)

=357x3988678

=1423958046

sai nha Hồng Hà Thi

(-357) + 27 + ( -357) + (-32)

= -330 + (-389)

= -719

Chúc bạn học tốt

(5¹⁵\(\times\) 4 + 15¹⁵): 5¹⁶

= (5¹⁵.4 + 3¹⁵.5¹⁵): 5¹⁶

= 5¹⁵.( 4 + 3¹⁵):5¹⁶

= (5¹⁵: 5¹⁶).(4 + 3¹⁵)

= \(\dfrac{1}{5}\).(4 + 3¹⁵)

515$\times$ 4 + 1515): 516

= (515.4 + 315.515): 516

= 515.( 4 + 315):516

= (515: 516).(4 + 315)

= $\genfrac{}{}{0ex}{}{1}{5}$.(4 + 315

a) $420-(71+420)$

$=420-71-420$

$=-71$

b) $(35-120)+(120+410-35)$

$=35-120+120+410-35$

$=(35-35)+(-120+120)+410$

$=410$

c) $(320-15+49)-(85-51)$

$=320-15+49-85+51$

$=320+(-15-85)+(49+51)$

$=320+(-100)+100$

$=320$

d) $-(312+59)-(41+400+88)$

$=-312-59-41-400-88$

$=(-312-88)+(-59-41)-400$

$=-400+(-100)-400$

$=-500-400$

$=-900$

e) $(430-731)-(-731+430-56)$

$=430-731+731-430+56$

$=(430-430)+(-731+731)+56$

$=56$

f) $(1352-47)-(53-1000+1352)$

$=1352-47-53+1000-1352$

$=(1352-1352)+(-47-53)+1000$

$=(-100)+1000$

$=1000-100$

$=900$

h) $(-42)-(370+58)-(120-370)$

$=-42-370-58-120+370$

$=(-42-58)+(-370+370)-120$

$=-100-120$

$=-220$

$Toru$

Chịu