24.55+5 mũ 2.53
Thực hiện phép tính:
a) {[(37 + 13) : 5] - 45 : 5} .7
62.10 : {780 : [103 - (2.53 + 35.14)]}
\(a,\left\{\left[\left(37+13\right):5\right]-45:5\right\}.7\)
\(=\left\{\left[50:5\right]-45:5\right\}.7\)
\(=\left\{10-45:5\right\}.7\)
\(=\left\{10-9\right\}.7\)
\(=1.7=7\)
\(6^2.10:\left\{780:\left[10^3-\left(2.5^3+35.14\right)\right]\right\}\)
\(=36.10:\left\{780:\left[1000-\left(2.125+35.14\right)\right]\right\}\)
\(=360:\left\{780:\left[1000-\left(250+490\right)\right]\right\}\)
\(=360:\left\{780:\left[1000-740\right]\right\}\)
\(=360:\left\{780:260\right\}\)
\(=360:3=120\)
Thực hiện phép tính:
a)23.15 - [115-(12-5)2 ]
b) 100 : {250 : [450 - (2.53 - 23.25)]}
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
=
\(a,2^3.15-\left[115-\left(12-5\right)^2\right]\)
\(=8.15-\left[115-\left(12-5\right)^2\right]\)
\(=120-\left[115-7^2\right]\)
\(=120-\left[115-49\right]\)
\(=120-66\)
\(=54\)
\(b,100:\left\{250:\left[450-\left(2.5^3-2^3.25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-\left(2.125-8.25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-\left(250-200\right)\right]\right\}\)
\(=100:\left\{250:\left[450-50\right]\right\}\)
\(=100:\left\{250:400\right\}\)
\(=100:0,625\)
\(=160\)
a: \(2^3\cdot15-\left[115-\left(12-5\right)^2\right]\)
\(=8\cdot15-115+7^2\)
\(=54\)
b: \(100:\left\{250:\left[450-\left(2\cdot5^3-2^3\cdot25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-50\right]\right\}\)
\(=100:\left\{250:400\right\}\)
\(=100:\dfrac{5}{8}=160\)
62. 10 : {780 : [103 - (2.53 + 35 . 14)]}
\(62\cdot10:\left\{780:\left[103-\left(2\cdot53+35\cdot14\right)\right]\right\}\)
\(=62\cdot10:\left\{780:\left[103-596\right]\right\}\)
\(=620:\dfrac{-780}{493}\)
\(=620\cdot\dfrac{-493}{780}=\dfrac{-15283}{39}\)
so sánh 1.3.5.7.....99 và 51/2.52/2.53/2.....100/2
C=1.3.5.7.....99 và D=51/2.52/2.53/2....100/2
tổng của 3 số là 188.75. số 1 bé hơn 2 số kia là 17.35 . Số 3 kém số 2 là 24.55 . tìm số thứ 3
So sánh C = 1.3.5.7...99 với D = 51/2.52/2.53/2...100/2
So sánh:
C= 1.3.5.7...9 với D= 51/2.52/2.53/2...100/2
-->C=\(\frac{1.2.3.4...99.100}{2.4.6....100}\)-->C=\(\frac{1.2.3...99.100}{\left(2.2....2\right)\left(1.2.3.4.5....50\right)}\)[50 chữ số 2]
-->\(C=\frac{51}{2}.\left(\frac{52}{2}\right)....\left(\frac{100}{2}\right)\)=D vậy C=D
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LI-KE CHO MK NHÉ BN
cho C=1.3.5.7...99 và D=51/2.52/2.53/2...100/2
So sánh CvaD
C=1.3.5.7...99
=>2.4.6...100.C=1.2.3...100
=>C = (1.2.3....100) / (2.4.6...100)= (1.2.3...50).(51.52...100) / [(2.1)(2.2).(2.3)...(2.50)]
C=(1.2.3...50).(51.52...100) /[2^50.(1.2.3...50)] =(51.52...100)/2^50 =51/2.52/2.53/2...100/2 =D
VAy C=D