Tính nhanh:
25+25+25+25=?
Tính nhanh:
25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25
25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25
= 25 x 10
= 250
tính nhanh :[viết cách làm nha]
25+25+25+25+25+25+25+25+25+25=?
25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 + 25 = ?
= 25 x 10
= 250
25 + 25 + 25 + ..... + 25 (10 số 25) = 25 x 10
= 250
Bài 1.2: Tính nhanh:
5+ 5 + 5 + 5+ 5 + 5 +5+ 5 + 5 +5
25 + 25 + 25 + 25 + 25 + 25 +25 + 25
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
5+ 5 + 5 + 5+ 5 + 5 +5+ 5 + 5 +5=5x10=50
25 + 25 + 25 + 25 + 25 + 25 +25 + 25=25x8=200
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15=(45x4)+(15x4)=180+60=240
5+ 5 + 5 + 5+ 5 + 5 +5+ 5 + 5 +5
= 5 x 10
= 50
25 + 25 + 25 + 25 + 25 + 25 +25 + 25
= 25 x 8
= 200
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
= 45 x 4 + 15 x 4
= 180 + 60
= 240
2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
= (2 + 18) + (4 + 16) + (8 + 12) + (6 + 14) + 10
= 20 + 20 + 20 + 20 + 10
= 20 x 4 + 10
= 80 + 10
= 90
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= 4 x (125 - 25)
= 4 x 100
= 400
(Tick cho mk pls ^^)
Tính nhanh:
64×25+35×25+25
64*25+35*25+25
=25*(64+35+1)
=25*100
=2500
Tính nhanh:
12 . 25 + 29 . 25 + 59 . 25
12.25+29.25+59.25
=25.(12+29+59)
=25.100
=2500.
tính nhanh: (25-12 ) x ( 25- 22) x ... x ( 25-1002)
Tính nhanh: \(\frac{25}{72}+\frac{25}{90}+\frac{25}{110}+\frac{25}{132}+...+\frac{25}{9900}\)
\(\frac{25}{72}+\frac{25}{90}+\frac{25}{110}+...+\frac{25}{9900}\)
= \(25.\left(\frac{1}{72}+\frac{1}{90}+\frac{1}{110}+...+\frac{1}{9900}\right)\)
= \(25.\left(\frac{1}{8.9}+\frac{1}{9.10}+\frac{1}{10.11}+...+\frac{1}{99.100}\right)\)
= \(25.\left(\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}+\frac{1}{10}-\frac{1}{11}+...+\frac{1}{99}-\frac{1}{100}\right)\)
= \(25.\left(\frac{1}{8}-\frac{1}{100}\right)\)
= \(25.\frac{23}{200}\)
= \(\frac{23}{8}\)
48×25+53 ×25 -25
Tính nhanh
48 x 25 + 53 x 25 - 25
= 48 x 25 + 53 x 25 - 25 x 1
= 25 x ( 48 + 53 - 1 )
= 25 x ( 101 - 1 )
= 25 x 100
= 2500
48×25+53 ×25 -25
= 25x( 48+53-1 )
=25x100
=2500
48 x 25 + 53 x 25 - 25
= 48 x 25 + 53 x 25 - 25 x 1
= 25 x 48 + 25 x 53 - 25 x 1
= 25 x ( 48 + 53 - 1 )
= 25 x 100
= 2500
Tính nhanh :
25 x 25 + 10 x 25 + 89 = ?
25 x 25 + 10 x 25 + 89
= 25 x (25 + 10) + 89
= 25 x 35 + 89
= 875 + 89
= 964