\(\dfrac{7,5+1,5+\dfrac{5}{4}+\dfrac{5}{11}}{10,5+2,1+\dfrac{7}{4}+\dfrac{7}{11}}\)+ x =\(\dfrac{6}{7}\)
Câu 13. Tính:
a) $\dfrac{5}{7} . \dfrac{5}{11}+\dfrac{5}{7} . \dfrac{6}{11}-\dfrac{5}{7} . \dfrac{4}{11}$;
b) $1,2-3^2+7,5$ $:$ $3$.
a
=5/7 * (5+6-4/11)
= 5/7+7/11
=5/11
b
=1,2 - 9 + 2,5
= -7,8 + 2,5
= -5,3
a
=5/7 * (5+6-4/11)
= 5/7+7/11
=5/11
b
=1,2 - 9 + 2,5
= -7,8 + 2,5
= -5,3
a, 5/7 * (5/11+6/11-4/11)
= 5/7* (-3/11) = -15/77
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, \(\dfrac{4}{25}.\dfrac{5}{8}.\dfrac{25}{4}.24\)
\(=\left(\dfrac{4}{25}.\dfrac{25}{4}\right).\left(\dfrac{5}{8}.24\right)\)
\(=1.15=15\)
Tính nhanh:
\(a,A=\dfrac{\dfrac{5}{4}+\dfrac{5}{5}+\dfrac{5}{7}-\dfrac{5}{11}}{\dfrac{10}{4}+\dfrac{10}{5}+\dfrac{10}{7}-\dfrac{10}{11}}\)\(b,B=\dfrac{2+\dfrac{6}{5}-\dfrac{6}{7}-\dfrac{6}{11}}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\)
giúp mình với
\(a,A=\dfrac{\dfrac{5}{4}+\dfrac{5}{5}+\dfrac{5}{7}-\dfrac{5}{11}}{\dfrac{10}{4}+\dfrac{10}{5}+\dfrac{10}{7}-\dfrac{10}{11}}\\ =\dfrac{5.\left(\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{11}\right)}{10.\left(\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{11}\right)}\\ =\dfrac{5}{10}\\ =\dfrac{1}{2}\)
Vậy \(A=\dfrac{1}{2}\)
\(b,B=\dfrac{2+\dfrac{6}{5}-\dfrac{6}{7}-\dfrac{6}{11}}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\\ =\dfrac{3.\left(\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}\right)}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\\ =3\)
Vậy \(B=3\)
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`
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=1\times\dfrac{3}{7}=\dfrac{3}{7}\)
___________
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\)
\(=\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\)
\(=\dfrac{3}{5}\times\dfrac{5}{9}\)
\(=\dfrac{1}{3}\)
__________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\)
\(=\dfrac{2}{7}\times\dfrac{5}{2}\)
\(=\dfrac{5}{7}\)
\(#WendyDang\)
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=\dfrac{11}{11}\times\dfrac{3}{7}\\ =1\times\dfrac{3}{7}=\dfrac{3}{7}\)
_____
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\\ =\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\\ =\dfrac{3}{5}\times\dfrac{5}{9}\\ =\dfrac{3}{9}\\ =\dfrac{1}{3}\)
_________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\\ =\dfrac{2}{7}\times\dfrac{5}{2}\\ =\dfrac{10}{14}\\ =\dfrac{5}{7}\)
\(\dfrac{6}{7}\) + \(\dfrac{2}{3}\) 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
a) \(\dfrac{ 3}{ 4 }\)+\(\dfrac{ -7 }{ 5 }\)+\(\dfrac{ 1 }{ 4 }\)+\(\dfrac{ -3 }{ 5 }\) b) \(\dfrac{ 4 }{ 9 }.\dfrac{7 }{ 11 }-\dfrac{4 }{ 11 }.\dfrac{ 2 }{9 } + \dfrac{ 6 }{ 11 }.\dfrac{ 4 }{ 9 }\)
a) 3/4 + (-7/5) + 1/4 + (-3/5)
= (3/4 + 1/4) + (-7/5 - 3/5)
= 1 - 2
= -1
b) 4/9 . 7/11 - 4/11 . 2/9 + 6/11 . 4/9
= 4/9 . (7/11 - 2/11 + 6/11)
= 4/9 . 1
= 4/9
a)
\(\dfrac{3}{4}+\dfrac{-7}{5}+\dfrac{1}{4}+\dfrac{-3}{5}\)
\(=\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\left(\dfrac{-7}{5}-\dfrac{3}{5}\right)\)
\(=1-2\)
\(=-1\)
b)
\(\dfrac{4}{9}.\dfrac{7}{11}-\dfrac{4}{11}.\dfrac{2}{9}+\dfrac{6}{11}.\dfrac{4}{9}\)
\(=\dfrac{28}{99}-\dfrac{8}{99}+\dfrac{24}{99}\)
\(=\dfrac{28-8+24}{99}\)
\(=\dfrac{44}{99}\)
\(=\dfrac{4}{9}\)
405 : 27 x 516
\(\dfrac{6}{7}\) + \(\dfrac{2}{3}\) x \(\dfrac{5}{4}\)
\(\dfrac{9}{5}\) - \(\dfrac{6}{7}\) : \(\dfrac{11}{7}\)
\(405:27\times516=15\times516=7740\)
\(\dfrac{6}{7}+\dfrac{2}{3}\times\dfrac{5}{4}=\dfrac{6}{7}+\dfrac{5}{6}=\dfrac{71}{42}\)
\(\dfrac{9}{5}-\dfrac{6}{7}:\dfrac{11}{7}=\dfrac{9}{5}-\dfrac{6}{11}=\dfrac{69}{55}\)
1/Thực hiện phép tính:
𝒂) ( \(\dfrac{7}{5}\) − \(\dfrac{8}{7}\) ) + \(3\dfrac{2}{5}\) ∶ 𝟎,𝟔
b) \(\dfrac{11}{6}\) + \(\dfrac{7}{6}\) ∶ \(\dfrac{-5}{4}\)
c) \(\dfrac{7}{4}\) − \(\dfrac{5}{4}\) . \(\dfrac{8}{15}\)
2/ Tìm x biết
b) 𝒙 + 𝟐,𝟓 = \(\dfrac{-8}{3}\)
b) 𝟐𝒙 − 𝟐𝟎% = \(\dfrac{9}{5}\)
𝒄) ( \(\dfrac{5}{4}\) )2 + 𝒙 = \(2\dfrac{3}{4}\)
\(1\)/
\(a\)) \(=\left(\dfrac{7}{5}-\dfrac{8}{7}\right)+\dfrac{17}{5}:0,6\)
\(=\dfrac{9}{35}+\dfrac{17}{3}\)
\(=\dfrac{622}{105}\)
\(b\)) \(=\dfrac{11}{6}+\dfrac{-14}{15}\)
\(=\dfrac{9}{10}\)
\(c\)/ \(=\dfrac{7}{4}-\dfrac{2}{3}\)
\(=\dfrac{13}{12}\)
\(\left(\dfrac{2}{3}+\dfrac{2}{13}+\dfrac{2}{11}+\dfrac{2}{6}\right)\) \(\left(\dfrac{5}{4}+\dfrac{5}{7}+\dfrac{5}{6}+\dfrac{5}{11}\right)\)
___________________ 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 ________________________
\(4.\left(\dfrac{1}{3}+\dfrac{1}{13}+\dfrac{1}{11}+\dfrac{1}{6}\right)\) \(9.\left(\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{1}{6}\dfrac{1}{11}\right)\)
= \(\dfrac{2}{4}X\dfrac{5}{9}\)= \(\dfrac{10}{36}\)= \(\dfrac{5}{18}\)