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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 \(x=\dfrac{52}{5}\).
\(Toru\)
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
=
\(a,2^3.15-\left[115-\left(12-5\right)^2\right]\)
\(=8.15-\left[115-\left(12-5\right)^2\right]\)
\(=120-\left[115-7^2\right]\)
\(=120-\left[115-49\right]\)
\(=120-66\)
\(=54\)
\(b,100:\left\{250:\left[450-\left(2.5^3-2^3.25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-\left(2.125-8.25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-\left(250-200\right)\right]\right\}\)
\(=100:\left\{250:\left[450-50\right]\right\}\)
\(=100:\left\{250:400\right\}\)
\(=100:0,625\)
\(=160\)
\(2^3.15-\left[115-\left(12-5\right)^2\right]=8.15-\left[115-7^2\right]=120-\left[115-49\right]=120-66=54\)
\(100:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}=100:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}=100:\left\{250:\left[450-\left(500-100\right)\right]\right\}\)
\(=100:\left[250:\left(450-400\right)\right]=100:\left(250:50\right)=100:5=20\)
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
a: \(=\dfrac{5}{9}-\dfrac{12+5}{15}:\dfrac{6}{5}\)
\(=\dfrac{5}{9}-\dfrac{17}{15}\cdot\dfrac{5}{6}=\dfrac{5}{9}-\dfrac{17}{18}=-\dfrac{7}{18}\)
b: \(=\left[\dfrac{6}{5}\left(3+\dfrac{3}{8}-6-\dfrac{5}{8}\right)\right]\cdot\dfrac{5}{6}=-3-\dfrac{1}{4}=-\dfrac{13}{4}\)
\(160-\left(2^3.5^2-6.25\right)\)
\(=160-\left(8.25-6.25\right)\)
\(=160-\left[\left(8-6\right).25\right]\)
\(=160-\left[2.25\right]\)
\(=160-50\)
\(=110\)
~ Hok tốt ~
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