Tính nhanh
21/11*68/63*22/17
(27/25-4/9) - (2/25+5/9)
21/11*68/63*22/17
(27/25-4/9)-(2/25+5/9)
Tính bằng cách thuận tiện
\(\frac{21}{11}\times\frac{22}{17}\times\frac{68}{63}\)
=\(\frac{21}{1}\times\frac{2}{17}\times\frac{68}{63}\)
= 21 x \(\frac{8}{63}\)
=\(\frac{8}{3}\)
Dùng tính chất để tính
a) 17/5 . -31/125 . 1/2 . 10/17 . -1/23
b) (11/4 . -5/9 - 4/9 . 11/4) . 8/33
c) (17/28 + 18/29 - 19/30 - 20/31) . (-5/12 + 1/4 + 1/6)
d) -1/4 . 15^2/11 + 68/4 . -1/11
e) -9/25 . 53/3 - (-3/5)^2 .22/3
a) 21/11 x 22/17 x 68/63
b) 5/14 x 7/13 x 26/25
c) 7/9 x 3/35 x 17/9
d) 11/17 : 33/34
e) 15,7 : 6,28
a)\(\frac{8}{3}\)
b)\(\frac{1}{5}=0,2\)
c)\(\frac{17}{135}\)
d)\(\frac{2}{3}\)
e)\(\frac{5}{2}=2,5\)
a) 21/11 x 22/17 x 68/63
= (21 x 22 x 68)/ (11 x 17 x 63)
= 8/3
b) 5/14 x 7/13 x 26/25
= (5 x 7 x 26)/(14 x 13 x 25)
= (5 x 7 x 13 x 2) / ( 7 x 2 x 13 x 5 x 5)
= 1/5
c) 7/9 x 3/35 x 17/9
= (7 x 3 x 17)/ (9 x 35 x 9 )
= 17/135
d) 11/17 : 33/34
= 11/17 x 34/33
= (11 x 34)/(17 x 33)
= (11 x 17 x 2) / ( 17 x 33 x 11)
=2/33
e) 15,7 : 6,28
= 157/10 : 157/ 25
= 157/10 x 25/157
= (157 x 25) / ( 10 x 157)
= 25/10 = 5/2
k nha
tính hợp lý
-9/4 . 97/5 + (-3/2)2 . (-73/5) - (99/100)0
22/25 . (5/11 - 8/9) - 8/9 . (27/4 - 22/25)
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?
Tính bằng cách thuận tiện nhất
21/11 x 22 /17 x 68/63
5/14x7/13x6/25
21/11 x 22/17 x 68/63 = 952/357
5/14 x 7/13 x 6/25=3/65
\(\frac{21}{11}X\frac{22}{17}X\frac{68}{63}=\frac{952}{357} \)
\(\frac{5}{14}X\frac{7}{13}X\frac{6}{25}=\frac{3}{65}\)
22/25.(5/11-8/9)-8/9.(27/4-22/25)
\(\frac{22}{25}.\left(\frac{5}{11}-\frac{8}{9}\right)-\frac{8}{9}\left(\frac{27}{4}-\frac{22}{25}\right)\)
\(\frac{22}{25}.\left(\frac{5}{11}-\frac{8}{9}\right)-\frac{8}{9}.\left(\frac{27}{4}-\frac{22}{25}\right)=\frac{22}{25}.\frac{5}{11}-\frac{22}{25}.\frac{8}{9}-\frac{8}{9}.\frac{27}{4}+\frac{8}{9}.\frac{22}{25}=\frac{2}{5}-\frac{6}{1}=\frac{-28}{5}\)
22/25. (5/11-8/9)-8/9. (27/4-22/25)
hãy tính và rút gọn
5/14 *7/13*26/25
/11 *22/17*68/63