Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
các phân số bằng nhau là :
\(\frac{15}{25}=\frac{21}{35}=\frac{3}{5}=\frac{75}{125}\)
\(\frac{7}{4}=\frac{49}{28}=\frac{105}{60}\)
$\frac{{15}}{6} = \frac{{15:3}}{{6:3}} = \frac{5}{2}$
$\frac{{12}}{{16}} = \frac{{12:4}}{{16:4}} = \frac{3}{4}$
$\frac{{35}}{{105}} = \frac{{35:35}}{{105:35}} = \frac{1}{3}$
a)\(\dfrac{22}{25}+\dfrac{25}{125}+\dfrac{36}{96}\)
\(=\dfrac{22}{25}+\dfrac{1}{5}+\dfrac{3}{8}\)
\(=\dfrac{176}{200}+\dfrac{40}{200}+\dfrac{75}{200}\)
\(=\dfrac{291}{200}\)
b)\(\dfrac{22}{77}+\dfrac{56}{98}+\dfrac{25}{105}\)
\(=\dfrac{2}{7}+\dfrac{4}{7}+\dfrac{5}{21}\)
\(=\dfrac{6}{7}+\dfrac{5}{21}\)
\(=\dfrac{18}{21}+\dfrac{5}{21}=\dfrac{23}{21}\)
a) 35 : 5 và (35 x 4) : (5 x 4)
35:5= 7
(35 x 4) : (5 x 4) = 140 : 20 =7
=> 35 : 5 = (35 x 4) : (5 x 4)
b) 105 : 15 và (105 : 5) : (15 : 5)
105:15 =7
(105 : 5) : (15 : 5)= 7 : 3= 2 (dư 1)
=>105 : 15 > (105 : 5) : (15 : 5)
25 + 25 + 25 + 25 + 25 + 25 +25 + 25=25x8=200
45 + 45 + 45 + 45 + 15 + 15 + 15 + 15=(45x4)+(15x4)=180+60=240
1 : Tính nhanh:
a) 2376 + 3425 - 376 - 425 = ( 2376 - 376 ) + ( 3425 - 425 )
= 2000 + 3000
= 5000
b)4638 - 2437 + 5362 - 7563 = 2210 + ( - 2210 )
= 0
c) 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
= 45 x 4 + 15 x 4
= ( 45 + 15 ) x 4
= 60 x 4
= 240
d) 4 x 125 x 25 x 8 = ( 4 x 25 ) x ( 125 x 8 )
= 100 x 1000
= 100000
e) 2 x 8 x 50 x 25 x 125 = ( 2 x 50 ) x ( 8 x 125 ) x 25
= 100 x 1000 x 25
= 100000 x 25
= 2500000
2 : Tính nhanh bằng 2 cách:
C1 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= ( 125 - 25 ) + ( 125 - 25) + ( 125 - 25 ) + ( 125 - 25 )
=100 + 100 + 100 + 100
= 100 x 4
= 400
C2 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= 125 x 4 - 25 x 4
= ( 125 - 25 ) x 4
= 100 x 4
= 400
125+125+125+125-25-25-25-25=125×4-25×4=4×(125-25)=4×100=400
\(=\frac{\left(15+125\right).12:2}{14.11+14.19}\)
\(=\frac{840}{14.30}\)
\(=\frac{14.30.2}{14.30}\)
\(=2\)
\(\frac{15+25+35+...+125}{14.11+14.19}\)= \(\frac{\left(125+15\right).\left(\left(125-15\right):10+1\right):2}{14\left(11+19\right)}\)= \(\frac{140.12:2}{14.20}\)= \(\frac{840}{280}\)= 3