405 : 27 x 516
\(\dfrac{6}{7}\) + \(\dfrac{2}{3}\) x \(\dfrac{5}{4}\)
\(\dfrac{9}{5}\) - \(\dfrac{6}{7}\) : \(\dfrac{11}{7}\)
Tính giá trị biểu thức:
(\(\dfrac{6}{11}+\dfrac{5}{11}\)) x \(\dfrac{3}{7}\) \(\dfrac{3}{5}x\dfrac{7}{9}-\dfrac{3}{5}x\dfrac{2}{9}\) \(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\)
`(6/11 +5/11) xx 3/7`
`= 11/11xx 3/7`
`=1xx3/7`
`=3/7`
__
`3/5 xx 7/9 - 3/5 xx 2/9`
`= 3/5 xx (7/9-2/9)`
`= 3/5 xx 5/9`
`= 15/45`
`= 1/3`
__
`(6/7 -4/7):2/5`
`= 2/7 : 2/5`
`= 2/7 xx 5/2`
`= 10/14`
`= 5/7`
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=1\times\dfrac{3}{7}=\dfrac{3}{7}\)
___________
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\)
\(=\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\)
\(=\dfrac{3}{5}\times\dfrac{5}{9}\)
\(=\dfrac{1}{3}\)
__________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\)
\(=\dfrac{2}{7}\times\dfrac{5}{2}\)
\(=\dfrac{5}{7}\)
\(#WendyDang\)
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=\dfrac{11}{11}\times\dfrac{3}{7}\\ =1\times\dfrac{3}{7}=\dfrac{3}{7}\)
_____
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\\ =\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\\ =\dfrac{3}{5}\times\dfrac{5}{9}\\ =\dfrac{3}{9}\\ =\dfrac{1}{3}\)
_________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\\ =\dfrac{2}{7}\times\dfrac{5}{2}\\ =\dfrac{10}{14}\\ =\dfrac{5}{7}\)
a,\(\dfrac{1}{7}\text{x}\dfrac{2}{7}+\dfrac{1}{7}\text{x}\dfrac{5}{7}+\dfrac{6}{7}\) b,\(\dfrac{6}{11}\text{x}\dfrac{4}{9}+\dfrac{6}{11}\text{x}\dfrac{7}{9}-\dfrac{6}{11}\text{x}\dfrac{2}{9}\)
c, \(\dfrac{4}{25}\text{x}\dfrac{5}{8}\text{x}\dfrac{25}{4}\text{x}24\)
`a)1/7xx2/7+1/7xx5/7+6/7`
`=1/7xx(2/7+5/7)+6/7`
`=1/7xx1+6/7`
`=1/7+6/7=1`
`b)6/11xx4/9+6/11xx7/9-6/11xx2/9`
`=6/11xx(4/9+7/9-2/9)`
`=6/11xx9/9`
`=6/11`
Sorry nãy ghi thiếu.
`c)4/25xx5/8xx25/4xx24`
`=(4xx5xx25xx24)/(25xx8xx4)`
`=(4xx5xx24)/(4xx8)`
`=(5xx24)/8`
`=5xx3=15`
a, \(\dfrac{1}{7}.\dfrac{2}{7}+\dfrac{1}{7}.\dfrac{5}{7}+\dfrac{6}{7}\)
\(=\dfrac{1}{7}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{6}{7}\)
\(=\dfrac{1}{7}.1+\dfrac{6}{7}\)
\(=\dfrac{1}{7}+\dfrac{6}{7}=1\)
b, \(\dfrac{6}{11}.\dfrac{4}{9}+\dfrac{6}{11}.\dfrac{7}{9}-\dfrac{6}{11}.\dfrac{2}{9}\)
\(=\dfrac{6}{11}.\left(\dfrac{4}{9}+\dfrac{7}{9}-\dfrac{2}{9}\right)\)
\(=\dfrac{6}{11}.1=\dfrac{6}{11}\)
c, \(\dfrac{4}{25}.\dfrac{5}{8}.\dfrac{25}{4}.24\)
\(=\left(\dfrac{4}{25}.\dfrac{25}{4}\right).\left(\dfrac{5}{8}.24\right)\)
\(=1.15=15\)
\(\dfrac{6}{7}\) + \(\dfrac{2}{3}\) x \(\dfrac{5}{4}\)
\(\dfrac{9}{5}\) - \(\dfrac{6}{7}\): \(\dfrac{11}{7}\)
6/7+2/3.5/4
=6/7+5/6
=71/42
9/5-6/7:11/7
=9/5-6/11
=69/55
a: =6/7+10/12=72/84+70/84=142/84=71/42
b: =9/5-6/11=99/55-30/55=69/55
6/7+2/3×5/4=6/7+5/6=71/42
9/5−6/7:1/17=/95−6/11=69/55
Tính
a.\(\dfrac{4}{9}+\dfrac{3}{7}\) \(\dfrac{3}{4}+\dfrac{7}{24}\) \(\dfrac{1}{3}+\dfrac{2}{9}+\dfrac{4}{27}\)
b.\(\dfrac{5}{6}-\dfrac{3}{8}\) \(\dfrac{7}{15}-\dfrac{11}{30}\) \(\dfrac{2}{3}+\dfrac{1}{6}-\dfrac{7}{12}\)
c.\(\dfrac{18}{25}\times\dfrac{15}{6}\) \(\dfrac{30}{49}:\dfrac{6}{7}\) \(\dfrac{1}{2}\times\dfrac{3}{4}:\dfrac{6}{5}\)
d.\(8\times\dfrac{3}{5}:\dfrac{12}{5}\) \(4:\dfrac{9}{5}:\dfrac{10}{3}\)
3 bn đầu tiên xong mik sẽ tick
a: 4/9+3/7=28/63+27/63=55/63
3/4+7/24=18/24+7/24=25/24
1/3+2/9+4/27=9/27+6/27+4/27=19/27
b: 5/6-3/8=20/24-9/24=11/24
7/15-11/30=14/30-11/30=3/30=1/10
2/3+1/6-7/12
=8/12+2/12-7/12
=3/12=1/4
c: 18/25*15/6=15/25*18/6=3*3/5=9/5
30/49:6/7=30/49*7/6=210/294=5/7
1/2*3/4:6/5=3/8*5/6=15/48=5/16
d: 8*3/5:12/5=24/5*5/12=2
4:9/5:10/3=4*5/9*3/10=2/3
\(\dfrac{3}{7}\) + 4 = ?
\(\dfrac{5}{9}\) x 3 = ?
\(\dfrac{7}{8}\) - \(\dfrac{2}{9}\)= ?
5 - \(\dfrac{3}{4}\)= ?
\(\dfrac{5}{7}\) : 6 = ?
\(\dfrac{5}{6}\) x \(\dfrac{2}{7}\)= ?
3 + \(\dfrac{3}{4}\)= ?
\(\dfrac{3}{5}x\dfrac{4}{8}\) = ?
5 : \(\dfrac{3}{8}\)= ?
Mong mn trả lời
\(\dfrac{3}{7}+\dfrac{4}{1}=\dfrac{3}{7}+\dfrac{28}{7}=\dfrac{31}{7}\)
\(\dfrac{5}{9}\times3=\dfrac{5}{9}\times\dfrac{3}{1}=\dfrac{15}{9}=\dfrac{5}{3}\)
\(\dfrac{7}{8}-\dfrac{2}{9}=\dfrac{63}{72}-\dfrac{16}{72}=\dfrac{47}{72}\)
\(\dfrac{5}{1}-\dfrac{3}{4}=\dfrac{20}{4}-\dfrac{3}{4}=\dfrac{17}{4}\)
\(\dfrac{5}{7}:\dfrac{6}{1}=\dfrac{5}{7}\times\dfrac{1}{6}=\dfrac{5}{42}\)
\(\dfrac{5}{6}\times\dfrac{2}{7}=\dfrac{5\times2}{6\times7}=\dfrac{10}{42}=\dfrac{5}{21}\)
\(\dfrac{3}{1}+\dfrac{3}{4}=\dfrac{12}{4}+\dfrac{3}{4}=\dfrac{15}{4}\)
\(\dfrac{3}{5}\times\dfrac{4}{8}=\dfrac{3}{5}\times\dfrac{1}{2}=\dfrac{3\times1}{5\times2}=\dfrac{3}{10}\)
\(\dfrac{5}{1}:\dfrac{3}{8}=\dfrac{5}{1}\times\dfrac{8}{3}=\dfrac{40}{3}\)
a) \(\dfrac{3}{7}+4=\dfrac{3}{7}+\dfrac{4}{1}=\dfrac{3}{7}+\dfrac{28}{7}=\dfrac{31}{7}\)
b) \(\dfrac{5}{9}\times3=\dfrac{5\times3}{9}=\dfrac{15}{9}=\dfrac{5}{3}\)
c) \(\dfrac{7}{8}-\dfrac{2}{9}=\dfrac{63}{72}-\dfrac{16}{72}=\dfrac{47}{72}\)
d) \(5-\dfrac{3}{4}=\dfrac{5}{1}-\dfrac{3}{4}=\dfrac{20}{4}-\dfrac{3}{4}=\dfrac{17}{4}\)
e) \(\dfrac{5}{7}:6=\dfrac{5}{7}:\dfrac{6}{1}=\dfrac{5}{7}\times\dfrac{1}{6}=\dfrac{5}{42}\)
f) \(\dfrac{5}{6}\times\dfrac{2}{7}=\dfrac{5\times2}{6\times7}=\dfrac{10}{42}=\dfrac{5}{21}\)
g) \(3+\dfrac{3}{4}=\dfrac{3}{1}+\dfrac{3}{4}=\dfrac{12}{4}+\dfrac{3}{4}=\dfrac{15}{4}\)
h) \(\dfrac{3}{5}\times\dfrac{4}{8}=\dfrac{3\times4}{5\times8}=\dfrac{12}{40}=\dfrac{3}{10}\)
i) \(5:\dfrac{3}{8}=\dfrac{5}{1}:\dfrac{3}{8}=\dfrac{5}{1}\times\dfrac{8}{3}=\dfrac{40}{3}\)
\(\dfrac{-1}{3}.\dfrac{2}{5}\)
\(\dfrac{-3}{7}.\dfrac{4}{15}\)
\(\dfrac{-9}{3}.\dfrac{15}{27}\)
\(\dfrac{-5}{6}.\)( -12 )
\(\dfrac{-12}{4}.\dfrac{8}{9}\)
\(-3.\dfrac{7}{6}\)
\(\dfrac{-15}{9}.\dfrac{27}{5}\)
\(-9.\dfrac{4}{27}\)
-2/15
-4/35
-5/3
10
-8/3
-7/2
-9
-4/3
Chúc em học giỏi
\(=\dfrac{-2}{15}\\ =\dfrac{-4}{35}\\ =-1\\ =10\\ =\dfrac{-8}{3}\\ =-7\\ =-9\\ =\dfrac{-4}{3}\)
\(\left(\dfrac{2}{3}+\dfrac{2}{13}+\dfrac{2}{11}+\dfrac{2}{6}\right)\) \(\left(\dfrac{5}{4}+\dfrac{5}{7}+\dfrac{5}{6}+\dfrac{5}{11}\right)\)
___________________ X ___________________
\(\left(\dfrac{4}{3}+\dfrac{4}{13}+\dfrac{4}{11}+\dfrac{4}{6}\right)\) \(\left(\dfrac{9}{4}+\dfrac{9}{7}+\dfrac{9}{6}\dfrac{9}{11}\right)\)
ta có
\(2.\left(\dfrac{1}{3}+\dfrac{1}{13}+\dfrac{1}{11}+\dfrac{1}{6}\right)\) \(5.\left(\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{1}{6}+\dfrac{1}{11}\right)\)
_______________________ X ________________________
\(4.\left(\dfrac{1}{3}+\dfrac{1}{13}+\dfrac{1}{11}+\dfrac{1}{6}\right)\) \(9.\left(\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{1}{6}\dfrac{1}{11}\right)\)
= \(\dfrac{2}{4}X\dfrac{5}{9}\)= \(\dfrac{10}{36}\)= \(\dfrac{5}{18}\)
Bài 15:
a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)
b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2
Bài 16
a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)
b) x + \(\dfrac{3}{22}\)= \(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)
c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)
d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)
Bài 17: tìm x
a) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\): \(\dfrac{3}{56}\)
b) \(\dfrac{1}{5}\) : x=\(\dfrac{1}{5}\)+\(\dfrac{1}{7}\)
bài 18:
a)\(\dfrac{2}{5}\)+\(\dfrac{3}{4}\): x =\(\dfrac{-1}{2}\)
b)\(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\)x + \(\dfrac{3}{5}\)x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\).x-x = \(\dfrac{-9}{14}\)
bài 19: tính
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+\(\dfrac{1}{3.4}\)+...+ \(\dfrac{1}{2018.2019}\)
bài 20:tìm x
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+\(\dfrac{1}{x.\left(x+1\right)}\)=\(\dfrac{2008}{2009}\)
bài 21: tìm x
\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)\(\dfrac{x+3}{97}\)\(\dfrac{x+4}{96}\)=-4
bài 22 : so sánh các phân số sau:
a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\)và 1
b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)
c)\(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)
d) \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2
a,\(\dfrac{4}{9}\) : \(\dfrac{3}{10}\)
b,\(\dfrac{3}{7}\) x \(\dfrac{5}{7}\)
c,\(\dfrac{4}{9}\) : \(\dfrac{3}{2}\)
D \(\dfrac{3}{9}\) + \(\dfrac{5}{6}\) x \(\dfrac{2}{3}\)
E \(\dfrac{2}{7}\) x \(\dfrac{4}{3}\) + \(\dfrac{2}{6}\)
G \(\dfrac{4}{7}\) : 2 + \(\dfrac{4}{7}\)
a)\(=\dfrac{4}{9}\times\dfrac{10}{3}=\dfrac{40}{27}\)
b)\(\dfrac{3}{7}\times\dfrac{5}{7}=\dfrac{15}{49}\)
c)\(\dfrac{4}{9}:\dfrac{3}{2}=\dfrac{4}{9}\times\dfrac{2}{3}=\dfrac{8}{27}\)
a, =40/27
b, =15/49
c, =8/27
d, =3/9 +5/9
e, = 8/21 +2/6=5/7
g, =2/7+4/7=6/7