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18 tháng 7 2019

a,  600 : { 450 : 450 - 4 . 5 3 - 2 3 . 5 2 }

= 600:{450:[450 - (4.125 - 8.25)]} = 600:{450:[450 - (500 - 200)]}

= 600:{450:[450 - 300]} = 600:{450:150} = 600:3 = 200

b,  18 . { 420 : 6 - 150 - ( 68 . 2 - 2 3 . 5 ) }

= 18.{70 - [150 - (68.2 - 8.5)]} = 18.{70 - [150 - (136 - 40)]}

= 18.{70 - [150 - 96]} = 18.{70 - 54} = 18.16 = 288

17 tháng 8 2021

a) = 8 . 15 - [115- 72 ]

     = 8 . 15 - [115- 49 ]

     = 120    - 56

      = 64

b) = 100 : {250 : [450 - (2.125 - 8.25)]}

    = 100 : {250 : [450 - (250 - 200 )]}

     = 100 : {250 : [450 - 50]}

     = 100 : {250 :400}

     = 100 : 0,265

      = 0,00265

     = 

     

17 tháng 8 2021

\(a,2^3.15-\left[115-\left(12-5\right)^2\right]\)

\(=8.15-\left[115-\left(12-5\right)^2\right]\)

\(=120-\left[115-7^2\right]\)

\(=120-\left[115-49\right]\)

\(=120-66\)

\(=54\)

\(b,100:\left\{250:\left[450-\left(2.5^3-2^3.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(2.125-8.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(250-200\right)\right]\right\}\)

\(=100:\left\{250:\left[450-50\right]\right\}\)

\(=100:\left\{250:400\right\}\)

\(=100:0,625\)

\(=160\)

 

18 tháng 8 2021

Mik làm 1 câu thôi sức ko

18 tháng 8 2021

\(2^3.15-\left[115-\left(12-5\right)^2\right]=8.15-\left[115-7^2\right]=120-\left[115-49\right]=120-66=54\)

\(100:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}=100:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}=100:\left\{250:\left[450-\left(500-100\right)\right]\right\}\)

\(=100:\left[250:\left(450-400\right)\right]=100:\left(250:50\right)=100:5=20\)

7 tháng 10 2023

Bài 1.

\(a,\left(2^4\cdot3\cdot5^2\right):\left\{450:\left[450-\left(4\cdot5^3-2^3\cdot5^2\right)\right]\right\}\)

\(=\left(16\cdot3\cdot25\right):\left\{450:\left[450- \left(4\cdot125-8\cdot25\right)\right]\right\}\)

\(=\left(48\cdot25\right):\left\{450:\left[450-\left(500-200\right)\right]\right\}\)

\(=1200:\left[450:\left(450-300\right)\right]\)

\(=1200:\left(450:150\right)\)

\(=1200:3\)

\(=400\)

\(---\)

\(b,3^3\cdot5^2-20\left\{90-\left[164-2\cdot\left(7^8:7^6+7^0\right)\right]\right\}\)

\(=27\cdot25-20\left\{90-\left[164-2\cdot\left(7^2+1\right)\right]\right\}\)

\(=675-20\left\{90-\left[164-2\cdot\left(49+1\right)\right]\right\}\)

\(=675-20\left[90-\left(164-2\cdot50\right)\right]\)

\(=675-20\left[90-\left(164-100\right)\right]\)

\(=675-20\left(90-64\right)\)

\(=675-20\cdot26\)

\(=675-520\)

\(=155\)

\(---\)

\(c,\left[\left(18^7:18^6-17\right)\cdot2022-1986\right]\cdot5\cdot1^{2022}-13^2\cdot2020^0\)

\(=\left[\left(18-17\right)\cdot2022-1986\right]\cdot5\cdot1-169\cdot1\)

\(=\left(1\cdot2022-1986\right)\cdot5-169\)

\(=\left(2022-1986\right)\cdot5-169\)

\(=36\cdot5-169\)

\(=180-169\)

\(=11\)

Bài 2.

\(a) (2^x+1)^2+3\cdot(2^2+1)=2^2\cdot10\\\Rightarrow (2^x+1)^2+3\cdot(4+1)=4\cdot10\\\Rightarrow (2^x+1)^2+3\cdot5=40\\\Rightarrow (2^x+1)^2+15=40\\\Rightarrow (2^x+1)^2=40-15\\\Rightarrow (2^x+1)^2=25\\\Rightarrow (2^x+1)^2= (\pm 5)^2\\\Rightarrow \left[\begin{array}{} 2^x+1=5\\ 2^x+1=-5 \end{array} \right.\\ \Rightarrow \left[\begin{array}{} 2^x=4\\ 2^x=-6 (vô.lí) \end{array} \right. \\ \Rightarrow 2^x=2^2\\\Rightarrow x=2\)

Vậy \(x=2\).

\(---\)

\(b)3\cdot(x-7)+2\cdot(x+5)=41\\\Rightarrow 3\cdot x+3\cdot(-7)+2\cdot x+2\cdot5=41\\\Rightarrow 3x-21+2x+10=41\\\Rightarrow (3x+2x)+(-21+10)=41\\\Rightarrow 5x-11=41\\\Rightarrow 5x=41+11\\\Rightarrow 5x=52\\\Rightarrow x=\dfrac{52}{5}\)

Vậy \(x=\dfrac{52}{5}\).

\(Toru\)

14 tháng 9 2023

a) \(26+173+74+27\)

\(=\left(26+74\right)+\left(173+27\right)\)

\(=100+200\)

\(=300\)

b) \(75\cdot37+89\cdot46+75\cdot52-89\cdot21\)

\(=75\cdot\left(37+52\right)+89\cdot\left(46-21\right)\)

\(=75\cdot89+89\cdot25\)

\(=89\cdot\left(75+25\right)\)

\(=89\cdot100\)

\(=8900\)

c) \(2^7:2^2+5^4:5^3\cdot2^4-3\cdot2^5\)

\(=2^{7-2}+5^{4-3}\cdot2^4-3\cdot2^5\)

\(=2^5+5\cdot2^4-3\cdot2^5\)

\(=2^4\cdot\left(2+5-3\cdot2\right)\)

\(=2^4\cdot\left(7-6\right)\)

\(=2^4\)

\(=16\)

d) \(100:\left\{250:\left[450-\left(4\cdot5^3-2^2\cdot25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(4\cdot5^3-4\cdot5^2\right)\right]\right\}\)

\(=100:\left[250:\left(450-4\cdot5^2\cdot4\right)\right]\)

\(=100:\left[250:\left(450-400\right)\right]\)

\(=100:\left(250:50\right)\)

\(=100:5\)

\(=20\)

7 tháng 10 2016

B = 600 : { 450 : [450 - ( 4 . 53 - 23 . 5) ] }

B = 600 : { 450 : [ 450 - ( 4 . 125 - 8 . 25 ) ] }

B = 600 : { 450 : [ 450 - ( 500 - 200 ) ] }

B = 600 : { 450 : [ 450 - 300 ] }

B = 600 : { 450 : 150 }

B = 600 : 3

B = 200

7 tháng 10 2016

\(B=600:\left\{450:\left[450-\left(4.5^3-2^3.5^2\right)\right]\right\}\)

\(B=600:\left\{450:\left[450-300\right]\right\}\)

\(B=600:\left(450:150\right)\)

\(B=600:3\)

\(B=200\)

28 tháng 7 2019

a, 32 . 5 - 2x . 6 + 183 

= 9 . 5 - 2x . 6 + 1

= 45 - 2x . 6 + 1

= 45 - 2x + 1 . 3 + 1

=  3( 15 -  2x + 1) + 1

b, 100 : { 280 : [ 450 - ( 480 - 4 . 52 ) ] }

= 100 : { 280 : [ 450 - 380  ] }

= 100 : { 280 : 70 }

= 100 : 4 = 25

c, 8 . { 24 - [ 3 . ( 5 + 25 ) + 15 ] : 15 }

= 8 .   { 24 - [ 3 . 30 + 15 ] : 15 } 

= 8 . { 24 - 105 : 15 }

= 8 . { 24 - 7 }

= 8 . 17 = 136

21 tháng 7 2015

**** đi giúp cho                

21 tháng 7 2015

đừng bao giờ **** khi chưa có bài làm, nhé

11 tháng 7 2016

312 + (146 -X ) =401

11- (15 + 21 ) + X- (25-9)

2- X +177 - (-5) 

X -12 = (-9) - 15