Tìm X biết: a). X - 1313/2424 = 1717/3434
B). X - 4545/5454 = 1313/3939
a)X:(111-99)=17x5
b)(509 + 355):X =840 :35
c)(X+1)+(X+2)+(X+3)+..(X+28) =462
d)890:X =35 dư 15
rut gon cac phân số
12/36
75/300
121/1111
1313/1717
303/3003
1515/2424
\(\frac{12}{36}=\frac{1}{3}\) ; \(\frac{75}{300}=\frac{1}{4}\) ; \(\frac{1313}{1717}=\frac{13}{17}\) ; \(\frac{1515}{2424}=\frac{15}{24}\); \(\frac{121}{1111}=\frac{11}{101}\) \(\frac{303}{3003}=\frac{101}{1001}\)
a,X=1020
b,X=20736
c,d, tự làm
\(\frac{1}{3};\frac{1}{4};\frac{11}{101};\frac{13}{17};\frac{101}{1001};\frac{5}{8}\)
Tính nhanh :
1313/1717 x 171717/191919 x 19/13
( đáp án thôi )
\(=\dfrac{13}{17}\cdot\dfrac{17}{19}\cdot\dfrac{19}{13}=1\)
> , < , =
1313/1717.... 13/17
161616/202020.... 5/6
1414/1818.....7/8
1212/1616..... 1515/2424
1313/1717=13/17
=>1313/17 = 13/17
161616/202020 =16/20=4/5=24/30 ;5/6=25/30
=>161616/202020 <5/6
Tính giá trị biểu thức sau:
17 x (\(\dfrac{1313}{5151}\) + \(\dfrac{1111}{3434}\) ) : \(\dfrac{117}{512}\)
17 \(\times\) ( \(\dfrac{1313}{5151}\) + \(\dfrac{1111}{3434}\)) : \(\dfrac{117}{512}\)
= 17 \(\times\) ( \(\dfrac{1313:101}{5151:101}\) + \(\dfrac{1111:101}{3434:101}\)) : \(\dfrac{117}{512}\)
= 17 \(\times\) ( \(\dfrac{13}{51}\) + \(\dfrac{11}{34}\)): \(\dfrac{117}{512}\)
= 17 \(\times\) \(\dfrac{59}{102}\) \(\times\) \(\dfrac{512}{117}\)
= \(\dfrac{1003}{102}\) \(\times\) \(\dfrac{512}{117}\)
= \(\dfrac{15104}{351}\)
1313/1717 ..... 13/17 161616/202020 ....... 5/6
1414 ..... 7/8 1212/1616 ........1515/2424
1313/1717 = 13/17 161616/202020 < 5/6
1414 > 7/8 1212/1616 > 1515/2424
chúc bạn học tốt! ^_^
phần dưới cùng là cái underline đấy, ko phải dấu = đâu
tính nhanh tổng sau :
\(\frac{121212}{141414}\)x \(\frac{1313}{1212}\)x\(\frac{2424}{2424}\)
\(\frac{121212}{141414}\times\frac{1313}{1212}\times\frac{2424}{2424}\)
\(=\frac{6}{7}\times\frac{13}{12}\times1\)
\(=\frac{13}{14}\)
~ Hok tốt ~
=12. 10101/ 14.10101 . 13.101/12.101. 1
rút gọn ta được: 13/14
hok tốt
kt
giải thích tại sao: 1313/1717 = ( 1313 :101)/(1717:101)=13/17
mọi người giúp mình với mình đang cần gấp
Rút gọn các phân số sau:
a) − 1212 − 2424 ;
b) 120120 − 240240 ;
c) 1313 − 1414 .
a ) − 1212 − 2424 = ( − 1212 ) : ( − 1212 ) ( − 2424 ) : ( − 1212 ) = 1 2
b ) 120120 − 240240 = 120120 : ( − 120120 ) − 240240 : ( − 120120 ) = − 1 2
c) 1313 − 1414 = 1313 : ( − 101 ) − 1414 : ( − 101 ) = − 13 14
1313/1717 : 1/5
\(\dfrac{1313}{1717}\) : \(\dfrac{1}{5}\) = \(\dfrac{13}{17}\) : \(\dfrac{1}{5}\) = \(\dfrac{65}{17}\)
\(\dfrac{1313}{1717}\):\(\dfrac{1}{5}\)=\(\dfrac{13}{17}\)x5=\(\dfrac{65}{17}\)