a: 45+432+155+168

=45+155+432+168

=200+600

=800

b: \(5\cdot135-5\cdot35+175\)

\(=5\cdot\left(135-35\right)+175\)

\(=5\cdot100+175\)

=500+175

=675

c: \(129\cdot172-73\cdot129+129\)

\(=129\cdot\left(172-73+1\right)\)

\(=129\cdot100=12900\)

d: \(29\cdot73+110\cdot71+37\cdot29\)

\(=29\cdot\left(73+37\right)+110\cdot71\)

\(=29\cdot110+71\cdot110=110\cdot100=11000\)

e: \(12:\left\lbrace390:\left\lbrack500-\left(125+35\cdot7\right)\right\rbrack\right\rbrace\)

\(=12:\left\lbrace390:\left\lbrack500-\left(125+245\right)\right\rbrack\right\rbrace\)

\(=12:\left\lbrace390:\left\lbrack500-370\right\rbrack\right\rbrace=12:\left\lbrace\frac{390}{130}\right\rbrace=12:3=4\)

f: \(375:\left\lbrace32-\left\lbrack4+\left(5\cdot9-42\right)\right\rbrack\right\rbrace-14\)

\(=375:\left\lbrace32-\left\lbrack4+45-42\right\rbrack\right\rbrace-14=375:\left\lbrace32-7\right\rbrace-14\)

=375:25-14

=15-14

=1

a) = 217. [(-39) + (-61)]
= 217 . -100
= -21700

25.6.4.8.125

=(25.4).(125.8).6

=100.1000.6

=100000.6

=600000

\(25\cdot6\cdot4\cdot8\cdot125\)

\(=25\cdot4\cdot6\cdot8\cdot125\)

\(=100\cdot6\cdot1000\)

\(=100000\cdot6\)

\(=600000\)

1. Q=165+247+528+125+315

= 100+60+5+200+40+7+500+20+8+100+20+5+300+10+5

= ( 100+200+500+100+300) + ( 60+40+20+20+10 ) +( 5+7+8+5+5 )

= 1200+150+30

=1280

R=1234+5678+8+80

=1000+200+30+4+5000+600+70+8+8+80

= ( 1000+5000) + ( 200+600 ) + (30+70+80) + ( 4+8+8)

=6000+800+180+20

=7000

còn câu 2 mk lười lắm , bạn nhờ ngừi khác nha ^^ nhớ t i c k nha

Bài 1

Tính : Q=165+247+528+125+315 

=(165+125)+(247+315+528)

=290+1090

= 1380

R=1234+5678+8+80

=(1234+6)+(5678+2)+80

= 1240+5680+80

= (1240+60)+(5680+20)

=1300+5700=7000

Bài 2:

A= 243-97=(243+7)-(97-7)=250-90=160

B= 400-42-58=400-(42+58)=400-100=300

C=600-67-33=600-(67+33)=600-100=500

D=200-24-46=200-(24+46)=200-70=130

E=400-5-6-7-8=400-(5+6+7+8)=400-26=374

F= 764-115-268-43-32-20-85-37

=764-(115+85)-(268+32)-(43+37)-20

=764-200-300-80-20

=164

G=350-7-18-52-48-72

=350-(18+72)-(52+48)-7

=350-90-100-7

=160-7

=153

a: =-26+56=30

e: =-125+48+125-53=-5

B3:

a. =-1250000

b. =-20000

c. =0

d. =-24000

B4:

a. =-4100

b. =-2700

c. =400

d. =1007

=123+124+125-113-114-115

=(123-113)+ ​(124-114)+ (125-115)

=10+10+10

=30

\(\text{(123+ 124 + 125) – (113 + 114 + 115)}\)

\(=123+124+125-113-114-115\)

\(=\left(123-113\right)+\left(124-114\right)+\left(125-115\right)\)

\(=10+10+10=30.\)