=300

=200

=-4 

Ra đề sáng tạo đó

e)371+731-271-531

=(371-271)+(731-531)

=100+200

=300

e) = (371-271)+(731-531)

= 100 + 200 = 300

f) (57 - 17)+(58-18)+(59-19)+(60-20)+(61-21)

= 40+40+40+40+40 = 200

g) (9-10)+(11-12)+(13-14)+(15-16)

= -1+(-1)+(-1)+(-1)

= -4

a) tự làm

b) (57-17)+(58-18)+(59-19)+(60-20)+(61-21)=40+40+40+40+40=200

c) (9+15)+(11+13)+(-10-14)+(-12-12-4)=24+24-24-24-4=-4

d)-(1+2+3+.....+2007)=\(-\dfrac{\left(1+2007\right).2007}{2}=-2015028\)

đế nhá

a) \(13+22+\left(-20\right)+\left(-153\right)+8=13+22-20-153+8\)

\(=\left(13-153\right)+\left(22+8\right)-20=-140+30-20=-130\)

b) \(371+731+\left(-271\right)+\left(-281\right)=371+731-271-281\)

\(=\left(371-271\right)+\left(731-281\right)=100+450=550\)

c) \(9+\left(-10\right)+11+\left(-12\right)+13+\left(-14\right)+15+\left(-16\right)\)

\(=9-10+11-12+13-14+15-16\)

\(=\left(9-10\right)+\left(11-12\right)+\left(13-14\right)+\left(15-16\right)\)

\(=\left(-1\right)+\left(-1\right)+\left(-1\right)+\left(-1\right)=-4\)

a: =371-271-531+731=100+200=300

b: =-321-28-327+27

=-350-300

=650

c: =-424-371+424+29=-342

d: =-249+248=-1

a)371+(-271)+(-531)+731=300

b)-312+(-327+(-28)+27=650

c)-424+(-371)-(-424)-(-29)=-342

d)-249+197+248+(-197)=-1

e)3+(-5)+(-9)+11+(-13)=-13

g)-8+10+(-12)+14+(-16)+18=6

a) $371+731-271-531$

$=(371-271)+(731-531)$

$=100+200$

$=300$

b) $57+58+59+60+61-17-18-19-20-21$

$=(57-17)+(58-18)+(59-19)+(60-20)+(61-21)$

$=40+40+40+40+40$

$=40\cdot5$

$=200$

c) $9-10+11-12+13-14+15-16$

$=(9-10)+(11-12)+(13-14)+(15-16)$

$=-1+(-1)+(-1)+(-1)$

$=-1\cdot4$

$=-4$

$\text{#}Toru$

300

300

= 300