47x(23+50)-23x(47+50)

=47x23+47x50-23x47-23x50

=47x(23-23)-50x(47-23)

=47x0-50x24

=0-1200

=-1200

47 x(23 +50 )-23 x(47 +50)

=47x 23 +  47 x50 -23 x47 +23 x50

=0     

47.(23+50)-23.(47+50)

=47.23+47.50-23.47+23.50

=(47.23-23.47)+47.50+23.50

=(47.23-23.47)+(47+23).50

=0+70.50

=0+3500=3500.

a. = 23 . (55-45) + 230

    = 23 . 10 +230

    = 230 + 230

    = 460

b. = 71 . (66 - 41 - 1)

    = 71 . 24

    = 1704

c. = 50 . (11 + 22) - 100

    = 50 . 33 - 100

    = 1650 - 100

    = 1550

d. = 27. (54 - 50) + 50

    = 27 . 4 + 50

    = 108 + 50

    = 158

a) 23.55-45.23+230

    =23.(55-45)+230

    =23.10+230

    =230+230

    =460

b) 71.66-41.71-71

    =71.(66-41-1)

    =71.24

    =1704

c) 11.50+50.22-100

   =50.(11+22)-100

   =50.33-100

   =1550

d) 54.27-27.50+50

   =27.(54-50)+50

   =27.4+50

   =108+50

   =158

# Bé_Bông #

a, 23 . 55 -45 . 23 + 230

    23 . ( 55 - 45) + 230

    23 . 10 + 230

    230 + 230

    4600

b, 71 . 66 - 41 . 71  - 71

   71 . ( 66 - 71 - 1)

   71 . ( -4)

   -248

c, 11 . 50 + 50 . 22 - 100

    11 . ( 50 + 50 ) - 100

    11 . 100 - 100

    1100 - 100

    1000

d, 54 . 27 - 27 . 50 + 50

   27 . ( 54 - 50 ) + 50

   27 . 4 + 50

   108 + 50

   158

tck mk nhé

thank you

dễ vồn ..

    bằng 1200 bạn ak .. check mk nhé
 

47 x (23+50)-23x(47+50)

=47 x 73 - 23 x 97

=(97-47)x(73-23)

=50 x 50

=2500

 mình sai rùi!!!

ủng hộ nha

Cam on cau tra loi cua cac ban. Ai biet cach lam nho giup minh nhe,minh se h cho

ket qua la:

=495

=150

11+22+33+44+55+66+77+88+99

= ( 11 + 88 ) + ( 22 + 77 ) + ( 33 + 66 ) + ( 44 + 55 ) + 99

= 99 + 99 + 99 + 99 + 99

= 99 x 5 

= 495

10+20+30+40+50

= ( 10 + 40 ) + ( 20 + 30 ) + 50

= 50 + 50 + 50

= 50 x 3 

= 150

K mình nha mình nhanh nhất đó!

ai k mik mik ks lại

11+22+33+44+55+66+77+88+99

=(11+99)+(22+88)+(33+77)+(44+66)+55

=110+110+110+110+55

=110*4+55

=440+55

=495

10+20+30+40+50

=(10+50)+(20+40)+30

=60+60+30

=60*2+30

=120+30

=150

47.(23+50)-23.(47+50)

=47.23+47.50-23.47-23.50

=47.50-23.50

=50.(47-23)

=50.24=1200

47.(23+50)-23.(47+50)

= 47.23+47.50-23.47+23.50

= 47.50-23.50

= 50.(47-23)

=50.24

=5024

chúc bạn học tốt nhé

\(47.\left(23+50\right)-23.\left(47+50\right)\)

\(=47.73-23.97\)

\(=3431-2231\)

\(=1200\)

1.

a) \(125+80+375+220\)

\(=\left(125+375\right)+\left(80+220\right)\)

\(=500+300\)

\(=800\)

b) \(25.11.8.4.125\)

\(=\left(25.4\right).\left(8.125\right).11\)

\(=100.1000.11\)

\(=1100000\)

c) \(18.74+18.27-18\)

\(=18.\left(74+27-1\right)\)

\(=18.100\)

\(=1800\)

d) \(75.23+75.77-500\)

\(=75.\left(23+77\right)-500\)

\(=75.100-500\)

\(=7500-500\)

\(=7000\)

e) \(150:\left[25.\left(18-4^2\right)\right]\)

\(=150:\left[25.\left(18-16\right)\right]\)

\(=150:\left[25.2\right]\)

\(=150:50\)

\(=3\)

f) \(125.23.2.8.50\)

\(=\left(125.8\right).\left(2.50\right).23\)

\(=1000.100.23\)

\(=2300000\)

g) \(235+88+165+12\)

\(=\left(235+165\right)+\left(88+12\right)\)

\(=400+100\)

\(=500\)

h) \(71.32+71.68-1100\)

\(=71.\left(32+68\right)-1100\)

\(=71.100-1100\)

\(=7100-1100\)

\(=6000\)

i) \(6^7:6^6+4^3.2-24^0\)

\(=6+64.2-1\)

\(=6+128-1\)

\(=133\)

j) \(546-6.\left[158:\left(30+7^2\right)\right]\)

\(=546-6.\left[158:\left(30+49\right)\right]\)

\(=546-6.\left[158:79\right]\)

\(=546-6.2\)

\(=546-12\)

\(=534\)

k) \(268+147+132+253\)

\(=\left(268+132\right)+\left(147+253\right)\)

\(=400+400\)

\(=800\)

2. 

a) \(7x=707\)

\(x=707:7\)

\(x=101\)

b) \(6x+5=47\)

\(6x=47-5\)

\(6x=42\)

\(x=42:6\)

\(x=7\)

c) \(35:\left(x+1\right)=7\)

\(x+1=35:7\)

\(x+1=5\)

\(x=5-1\)

\(x=4\)

d) \(12+\left(29-3x\right)=35\)

\(29-3x=35-12\)

\(29-3x=23\)

\(3x=29-23\)

\(3x=6\)

\(x=6:3\)

\(x=2\)

e) \(2.4^x+10^1=138\)

\(2.4^x=138-10\)

\(2.4^x=128\)

\(4^x=128:2\)

\(4^x=64=4^3\)

\(\Rightarrow x=3\)

f) \(7x=140\)

\(x=140:7\)

\(x=20\)

g) \(7\left(15-x\right)+14=84\)

\(7\left(15-x\right)=84-14\)

\(7\left(15-x\right)=70\)

\(15-x=70:7\)

\(15-x=10\)

\(x=15-10\)

\(x=5\)

h) \(3^x.5-15=390\)

\(3^x.5=390+15\)

\(3^x.5=405\)

\(3^x=405:5\)

\(3^x=81=3^4\)

\(\Rightarrow x=4\)

3.

Ta có:

\(\Rightarrow n+11⋮n+1\)

\(\Rightarrow n+1+10⋮n+1\)

\(\Rightarrow10⋮n+1\) hay \(n+1\inƯ\left(10\right)=\left\{-10;-5;-2;-1;1;2;5;10\right\}\)

\(\Rightarrow\) \(n\in\left\{-11;-6;-3;-2;0;1;4;9\right\}\)

Vì \(n\in N\) nên \(n\in\left\{0;1;4;9\right\}\)

a. = 6.

Ta có:\(77^2+23^2+77.46\)

\(=77^2+2.23.77+23^2\)

\(=\left(77+23\right)^2\)

\(=100^2=10000\)

=77*77+23*23+77*46

=77*(77+46)+23*23

=77*123+23*23

=9471+529

=1000