Tính :
500 x 10=?
10 x 2 = ?
Tính nhẩm.
a) 2 100 : 10
4 500 : 100
83 000 : 1 000
b) 720 : 10 : 8
1 500 : (5 x 100)
60 000 : 1 000 x 6
a) 2 100 : 10 = 210
4 500 : 100 = 45
83 000 : 1 000 = 83
b) 720 : 10 : 8 = 72 : 8 = 9
1 500 : (5 x 100) = 1 500 : 5 : 100 = 300 : 100 = 3
60 000 : 1 000 x 6 = 60 x 6 = 360
Tính giá trị biểu thức :
a) 500 + 500 + 500 + ( 100 x 2 )
b) 700 + 300 + ( 100 x 10)
a, 500+500+500+(100 x 2)
=500 x 3+ 100x2
=1500+200
=1700
b, 700+300+(100 x 10)=700+300+1000=1000+1000=2000
k minh nha
Tìm x :
a) x . x . x = 125
b) ( x + 500 ) = 1000 - 200 .2
c) [( x + 10 ) . 100 ] = 500 + 500 . 10
a) x . x . x = 125
x3 =125
x3 = 53
= > x = 5
b) ( x + 500 ) = 1000 - 200 . 2
x + 500 = 1000 - 400
x + 500 = 600
x = 600 - 500
x = 100
c) [( x + 10 ) . 100 ] = 500 + 500 . 10
( x + 10 ) . 100 = 500 + 5000
( x + 10 ) . 100 = 5500
x + 10 = 5500 : 100
x + 10 = 55
x = 55 - 10
x = 45
Giá trị của \(x\) sao cho: 10 x 1 + 10 x 2 + … + 10 x 9 + 10 x 10 = 11 x \(x\) là
a/ 550 b/500 c/ 60 d/ 50
tính giá trị của tổng sau :
1/1 x 10 + 1/2 x 15 + 1/3 x 20 + ... + 1/89 x 495 + 1/ 99 x 500
\(\frac{1}{1\times10}+\frac{1}{2\times15}+\frac{1}{3\times20}+...+\frac{1}{98\times495}+\frac{1}{99\times500}\)
\(=\frac{1}{1\times2\times5}+\frac{1}{2\times3\times5}+\frac{1}{3\times4\times5}+...+\frac{1}{98\times99\times5}+\frac{1}{99\times100\times5}\)
\(=\frac{1}{5}\times\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{98\times99}+\frac{1}{99\times100}\right)\)
\(=\frac{1}{5}\times\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{98}-\frac{1}{99}+\frac{1}{99}-\frac{1}{100}\right)\)
\(=\frac{1}{5}\times\left(1-\frac{1}{100}\right)=\frac{1}{5}\times\frac{99}{100}=\frac{99}{500}\)
\(\frac{1}{1\times10}+\frac{1}{2\times15}+\frac{1}{3\times20}+...+\frac{1}{98\times495}+\frac{1}{99\times500}\)
\(=\frac{1}{1\times2\times5}+\frac{1}{2\times3\times5}+\frac{1}{3\times4\times5}+...+\frac{1}{98\times90\times5}+\frac{1}{90\times100\times5}\)
\(=\frac{1}{5}\times\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{98\times99}+\frac{1}{99\times100}\right)\)
\(=\frac{1}{5}\times\left(\frac{2-1}{1\times2}+\frac{3-2}{2\times3}+...+\frac{99-98}{98\times99}+\frac{100-99}{99\times100}\right)\)
\(=\frac{1}{5}\times\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{98}-\frac{1}{99}+\frac{1}{99}-\frac{1}{100}\right)\)
\(=\frac{1}{5}\times\left(1-\frac{1}{100}\right)=\frac{99}{500}\)
cảm ơn bạn Xyz và bạn Đoàn Đức Hà nhìu (^-^) thank you !!!!!!!!!!!!!!!!!
Tìm x : [ 500 : (x - 10) x 2 ] + 100 = 200
Tìm x :
[ 500 : (x - 10) x 2 ] + 100 = 200
=> 500 : ( x - 10 ) x 2 = 200 - 100
=> 500 : ( x - 10 ) x 2 = 100
=> 500 : ( x - 10 ) = 100 : 2
=> 500 : ( x - 10 ) = 50
=> x - 10 = 500 : 50
=> x - 10 = 10
=> x = 10 + 10
=> x = 20
Vậy x= 20
Tìm x : [ 500 : (x - 10) x 2 ] + 100 = 200
[500 : (x-10) x 2] + 100 = 200
500 : (x-10) x 2 = 100
=> 500 : (x-10) = 50
=> x - 10 = 10
=> x =20
Tính?
a) 24 x 30 36 x 40 72 x 60 89 x 50
Mẫu: 24 x 30 = (24 x 3) x 10 = 720
b) 130 x 20 450 x 70 2 300 x 500 17 000 x 30
Mẫu: 130 x 20 = (13 x 2) x 100 = 2 600
a,
36 x 40 = (36 x 4) x 10 = 144 x 10 = 1 440
72 x 60 = (72 x 6) x 10 = 432 x 10 = 4 320
89 x 50 = (89 x 5) x 10 = 445 x 10 = 4 450
b,
450 x 70 = (45 x 7) x 100 = 315 x 100 = 31 500
2300 x 500 = (23 x 5) x 10 000 = 115 x 10 000 = 1 150 000
17 000 x 30 = (17 x 3) x 10 000 = 510 000
Tính nhanh:
26,28 : 10% x 8,5 + 262,8 x 6,5 - 2,628 x 500
ai trả lời đúng mình sẽ tick cho
26,28 : 10% x 8,5 + 262,8 x 6,5 - 2,628 x 500
= 2628
#HT