23.17-23.14

=23.(17-14)

=23.3 = 69

23.(17-14)=23.3=69

a) 100 + (+430) + 2145 + (-530)

= 100 + [ (+430) + (-530) ] + 2145

= 100 + (-100) +2145

= 0 + 2145 = 2145

b) (-12) . 15 . 8 . (-4)

= [ (-12) . 8 ] . [ 15. (-4)]

= (-96) . (-60) = 5760

c) (+12) . 13 + 13 . (-22)

= 13. [ (+12) + (-22) ]

= 13. (-10) = -130

d) { [14 : (-2)] + 7 } : 2012

= { [ (-7) + 7 } : 2012

= 0 : 2012 = 0

e) -23 . 63 + 23 . 21 - 58 . 23

= 23 . -63 + 23 . 21 - 58.23

= 23. ( -63 + 21 - 58 )

= 23 . -100 = -2300

Hok tốt !

a) 100 + (+430) + 2145 + (-530)

=100+[430+(-530)]+2145

=100+(-100)+2145

=0+2145

=2145

b) (-12) . 15 . 8 . (-4)

=(-12.8).[15.(-4)]

=-90.(-60)

=5760

c) (+12) . 13 + 13 . (-22)

=13.[12+(-22)]

=13.(-10)

=-130

d) { [14 : (-2)] + 7 } : 2012

={-7+7}:2012

=0:2012

=0

e) -23 . 63 + 23 . 21 - 58 . 23

=23.(-63)+23.21-58.23

=23.(-63+21-58)

=23.(-100)

=-2300

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

dễ

\(a)24\times(x-16)=12^2\\\Rightarrow 24\times(x-16)=144\\\Rightarrow x-16=144:24\\\Rightarrow x-16=6\\\Rightarrow x=6+16\\\Rightarrow x=22\\---\\b)(x^2-10):5=5\\\Rightarrow x^2-10=5\times5\\\Rightarrow x^2-10=25\\\Rightarrow x^2=25+10\\\Rightarrow x^2=35\\\Rightarrow x=\pm\sqrt{35}\\---\)

\(c)(5x+335):2=400\\\Rightarrow 5x+335=400\times2\\\Rightarrow 5x+335=800\\\Rightarrow 5x=800-335\\\Rightarrow 5x=465\\\Rightarrow x=465:5\\\Rightarrow x=93\\---\\d)63:(5x+4)=2^3-1\\\Rightarrow 63:(5x+4)=8-1\\\Rightarrow 63:(5x+4)=7\\\Rightarrow 5x+4=63:7\\\Rightarrow 5x+4=9\\\Rightarrow 5x=9-4\\\Rightarrow 5x=5\\\Rightarrow x=5:5\)

\(\Rightarrow x=1\)

\(Toru\)

=3

=25

=47

1+2=3

12+13=25

23+24=47

k mk đã nha

1+2=3
12+13=25
23+24=47

nhiều quá mk phụ bạn chút thôi

a)47*(23+50)-23*(47+50)=47*23+47*50-23*47+23*50=(47*23-23*47)+(47*50+23*50)=(47+23)*50=70*50=3500

b)29*(85-47)+85*(47-29)=29*85-29*47+85*47-85*29=(29*85-85*29)+(85*47-29*47)=(85-29)*47=56*47=2632

c)37*90-37*(-10)=37*[90-(-10)]=37*100=3700

a. 47.[23+50]-23.[47+50]

=47.73-23.97

=3431-2231

=1200

b,29.[85-47]+85.[47-29]

=29.38+85.18

=1102+1520

=-428

c,37.90-37.[-10]

=37.(90-(-10))

=37.100

=3700

d,15.12-3.5.10

=15.12-15.10

=15.(12-10)

=15.2

=30

e,29.[19-13]-19.[29-13]

=29.6-19.16

=174-304

=-130

f,33.[17-5]-17.[33-5]

=33.12-17.32

=396-544

=-148

g,54-6.[17+9]

=54-6.26

=54-156

=-102

h,1000+[-570]+2341+[-430]

=430+2341+(-430)

=(-430+430)+2341

=0+2341

=2341

Đẹp lắm

cẩn thận bị trừ điểm đó nha vì đăng bài ko liên quan tới toán

Đẹp ơi là đẹp. Mwah!

(-23)+13+(-17)+57

=[(-23)+13]+[(-17)+57]

=(-10)+40

=30

hok tốt

Bạn ưi..

Tính cách nhanh hay tính bth cx ra kq là 30 mak

Chắc do bạn tính sai đó

Bạn kiểm tra lại xem

^^

(-23)+13+(-17)+57

C1: -23+13+(-17)+57

=(-23+13)+(-17+57)

=-10+40

=30

C2: -23+13+(-17)+57

=[-23+(-17)]+(13+57)

=-40+70

=30

^_^

1+6+23+4+95+98+456+17+54+68+29+​804+10+23+54=1742

là 1640 nha bn

Linh Nguyễn