số nguyên n thỏa mãn \(\dfrac{5}{9}< \dfrac{5}{n}< \dfrac{-3}{7}\) là
A.6 B.7 C.8 D.9
So sánh hai phân số:
a) \(\dfrac{5}{9}\) và \(\dfrac{7}{9}\) b) \(\dfrac{7}{6}\) và \(\dfrac{6}{6}\) c) \(\dfrac{3}{14}\) và \(\dfrac{5}{14}\) d) \(\dfrac{5}{8}\) và \(\dfrac{9}{8}\)
a) \(\dfrac{5}{9}< \dfrac{7}{9}\)
b) \(\dfrac{7}{6}>\dfrac{6}{6}\)
c) \(\dfrac{3}{14}< \dfrac{5}{14}\)
d) \(\dfrac{5}{8}< \dfrac{9}{8}\)
a)\(\dfrac{7}{8}\)x\(\dfrac{3}{13}\)+\(\dfrac{4}{9}\)x\(\dfrac{4}{13}\)
b)\(\dfrac{6}{5}\)+\(\dfrac{7}{3}\)+\(\dfrac{8}{9}\)
c)23: \(\dfrac{5}{14}\)+\(\dfrac{6}{7}\)+\(\dfrac{4}{9}\)
d)\(4\dfrac{1}{4}\)+\(7\dfrac{3}{7}\)-\(2\dfrac{4}{17}\)
e)8-(9\(\dfrac{2}{11}\)+\(\dfrac{8}{33}\))
a, \(\dfrac{7}{8}\) \(\times\) \(\dfrac{3}{13}\) + \(\dfrac{4}{9}\) \(\times\) \(\dfrac{4}{13}\)
= \(\dfrac{1}{13}\) \(\times\)( \(\dfrac{21}{8}\) + \(\dfrac{16}{9}\))
= \(\dfrac{1}{13}\) \(\times\)( \(\dfrac{189}{72}\) + \(\dfrac{128}{72}\))
= \(\dfrac{1}{13}\) \(\times\) \(\dfrac{317}{73}\)
= \(\dfrac{317}{949}\)
b, \(\dfrac{6}{5}\) + \(\dfrac{7}{3}\) + \(\dfrac{8}{9}\)
= \(\dfrac{54}{45}\) + \(\dfrac{105}{45}\) + \(\dfrac{40}{45}\)
= \(\dfrac{199}{45}\)
c, 23 : \(\dfrac{5}{14}\) + \(\dfrac{6}{7}\) + \(\dfrac{4}{9}\)
= \(\dfrac{322}{5}\) + \(\dfrac{6}{7}\) + \(\dfrac{4}{9}\)
= \(\dfrac{20286}{315}\) + \(\dfrac{270}{315}\) + \(\dfrac{140}{315}\)
= \(\dfrac{20696}{315}\)
d, 4\(\dfrac{1}{4}\) + 7\(\dfrac{3}{7}\) - 2\(\dfrac{4}{17}\)
= 4 + \(\dfrac{1}{4}\) + 7 + \(\dfrac{3}{7}\) - 2 - \(\dfrac{4}{17}\)
= (4+7-2) + (\(\dfrac{1}{4}\) + \(\dfrac{3}{7}\) - \(\dfrac{4}{17}\))
= 9 + \(\dfrac{119}{476}\) + \(\dfrac{204}{476}\) - \(\dfrac{112}{476}\)
= 9\(\dfrac{211}{476}\) = \(\dfrac{4495}{476}\)
e, 8 - (9\(\dfrac{2}{11}\) + \(\dfrac{8}{33}\))
= 8 - 9 - \(\dfrac{2}{11}\) - \(\dfrac{8}{33}\)
= -1 - \(\dfrac{2}{11}\) - \(\dfrac{8}{33}\)
= \(\dfrac{-33}{33}\) - \(\dfrac{-6}{33}\) - \(\dfrac{8}{33}\)
= - \(\dfrac{47}{33}\)
So sánh \(\dfrac{9}{170};\dfrac{9}{230};\dfrac{53}{144}\)
Số nguyên \(x\) thỏa mãn \(\left(\dfrac{3}{4}-\dfrac{2}{3}\right)+\dfrac{5}{6}\le x\le\dfrac{4}{5}-\left(\dfrac{3}{10}-\dfrac{5}{4}\right)\)
A. \(x=1\) B. \(x=0\) C. \(x=2\) D. \(x\in\left\{0;1\right\}\)
EM CẦN GẤP Ạ!
Tính:
a) \(\dfrac{3}{8}+\dfrac{7}{8}\) b) \(\dfrac{7}{9}-\dfrac{4}{9}\) c) \(\dfrac{5}{6}+\dfrac{1}{8}\) d) \(\dfrac{9}{15}-\dfrac{2}{5}\)
e) \(\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}\) g) \(\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}\) h) \(\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}\)
a: \(\dfrac{3}{8}+\dfrac{7}{8}=\dfrac{3+7}{8}=\dfrac{10}{8}=\dfrac{5}{4}\)
b: \(\dfrac{7}{9}-\dfrac{4}{9}=\dfrac{7-4}{9}=\dfrac{3}{9}=\dfrac{1}{3}\)
c: \(\dfrac{5}{6}+\dfrac{1}{8}=\dfrac{20}{24}+\dfrac{3}{24}=\dfrac{20+3}{24}=\dfrac{23}{24}\)
d: \(\dfrac{9}{15}-\dfrac{2}{5}=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{3-2}{5}=\dfrac{1}{5}\)
e: \(\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}=\dfrac{2+3+9}{5}=\dfrac{14}{5}\)
g: \(\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}=\dfrac{8-1-3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)
h: \(\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}=\dfrac{23-4+2}{7}=\dfrac{21}{7}=3\)
Có bao nhiêu số nguyên n thỏa mãn \(\dfrac{-5}{7}< \dfrac{n}{7}< \dfrac{-3}{7}\) ?
bài 1 :
a) \(\dfrac{2}{5}+\dfrac{3}{8}=\) b)\(\dfrac{7}{6}-\dfrac{2}{3}=\) c)\(\dfrac{5}{9}\times6\) d)\(\dfrac{8}{5}:\dfrac{4}{7}=\)
bài 2:
a) \(\dfrac{4}{5}+\) x =\(\dfrac{5}{6}\) b)x : \(\dfrac{7}{10}=5\)
bài 3 : hai xe ô tô chở được tất cả 16 tấn 8 tạ hàng . Xe ô tô thứ nhất chở được nhiều hơn xe ô tô thứ hai 2 tấn 6 tạ hàng . Hỏi mỗi xe chở được bao nhiêu tạ hàng
bài 4 :
145 \(\times\) 69 + 22 x 145 +145 x 8 + 145 =
bài 1
a)\(=\dfrac{16}{40}+\dfrac{15}{40}=\dfrac{31}{40}\)
b)\(=\dfrac{7}{6}-\dfrac{4}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)
c)\(=\dfrac{30}{9}=\dfrac{10}{3}\)
d)\(=\dfrac{8}{5}\times\dfrac{7}{4}=\dfrac{56}{20}=\dfrac{14}{5}\)
bài 2
a)\(x=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)
b)\(x=5\times\dfrac{10}{7}=\dfrac{50}{7}\)
bài 4 :
145 ×× 69 + 22 x 145 +145 x 8 + 145
\(=145\times\left(69+22+8+1\right)=145\times100=14500\)
bài 1:
a, \(\dfrac{2}{5}+\dfrac{3}{8}=\dfrac{16}{40}+\dfrac{15}{40}=\dfrac{31}{40}\)
b,\(\dfrac{7}{6}-\dfrac{2}{3}=\dfrac{7}{6}-\dfrac{4}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)
c,\(\dfrac{5}{9}x6=\dfrac{5}{9}x\dfrac{6}{1}=\dfrac{30}{9}\)
d,\(\dfrac{8}{5}:\dfrac{4}{7}=\dfrac{8}{5}x\dfrac{7}{4}=\dfrac{14}{5}\)
bài 2 :
\(a,\dfrac{4}{5}+x=\dfrac{5}{6}\)
\(x=\dfrac{5}{6}-\dfrac{4}{5}\)
\(x=\dfrac{1}{30}\)
b, \(x:\dfrac{7}{10}=5\)
\(x\) \(=5x\dfrac{7}{10}\)
\(x\) \(=\dfrac{35}{10}\)
bài 3 :
đổi :16 tấn 8 tạ = 168 tạ
2 tấn 6 tạ = 26 tạ
xe ô tô thứ nhất chở số tạ hàng là:
( 168 + 26 ) : 2= 97 ( tạ)
xe ô tô thứ hai chở số tạ hàng là:
97 - 26 = 71 ( tạ)
đáp số :xe ô tô thứ nhất : 97 tạ thóc
xe ô tô thứ hai : 71 tạ thóc
Tìm số nguyên x thỏa mãn
\(\dfrac{-9}{7}+\dfrac{5}{-7}< x\le\dfrac{-5}{2}+\dfrac{18}{4}\)
\(\dfrac{-9}{7}+\dfrac{5}{-7}< x\le\dfrac{-5}{2}+\dfrac{18}{4}\)
\(\dfrac{-9}{7}+\dfrac{-5}{7}< x\le\dfrac{10}{4}+\dfrac{18}{4}\)
\(\dfrac{-14}{7}< x\le2\)
\(-2< x\le2\)
\(\Rightarrow\)\(x=\left\{-1;0;1;2\right\}\)
a,\(\dfrac{7}{8}\)x\(\dfrac{2}{5}\)
b,\(\dfrac{9}{4}\)\(-\)\(\dfrac{5}{6}\)
c,\(\dfrac{4}{7}\)x\(\dfrac{2}{5}\)
d,\(\dfrac{3}{5}\)+2
e,4 \(-\) \(\dfrac{3}{5}\)
g,3x\(\dfrac{4}{9}\)
h,\(\dfrac{9}{5}\): 2
a. 7/8 x 2/5 =7/20
b.9/4-5/6=17/12
c.4/7x2/5=8/35
d.3/5+2=13/5
e. 4-3/5=17/5
g.3x4/9=4/3
h.9/5:2=9/10
a) \(\dfrac{14}{40}=\dfrac{7}{20}\)
b) \(\dfrac{27}{12}-\dfrac{10}{12}=\dfrac{17}{12}\)
c) \(\dfrac{8}{35}\)
d) \(\dfrac{3}{5}+\dfrac{10}{5}=\dfrac{13}{5}\)
e) \(\dfrac{20}{5}-\dfrac{3}{5}=\dfrac{17}{5}\)
g) \(\dfrac{12}{9}=\dfrac{4}{3}\)
h) \(\dfrac{9}{5}x\dfrac{1}{2}=\dfrac{9}{10}\)
`@LQuyen`
\(\dfrac{7}{8}\times\dfrac{2}{5}=\dfrac{14}{40}\)
\(\dfrac{9}{4}-\dfrac{5}{6}=\dfrac{54}{24}-\dfrac{20}{24}=\dfrac{34}{24}\)
\(\dfrac{4}{7}\times\dfrac{2}{5}=\dfrac{8}{35}\)
\(\dfrac{3}{5}+\dfrac{2}{1}=\dfrac{3}{5}+\dfrac{10}{5}=\dfrac{13}{5}\)
\(\dfrac{4}{1}-\dfrac{3}{5}=\dfrac{20}{5}-\dfrac{3}{5}=\dfrac{17}{5}\)
\(3\times\dfrac{4}{9}=\dfrac{12}{9}\)
\(\dfrac{9}{5}:2=\dfrac{9}{10}\)
A,\(\dfrac{8}{9}:\dfrac{4}{5}+\dfrac{3}{5}\)
B,\(\dfrac{5}{8}\) + \(\dfrac{1}{4}\)
C,\(\dfrac{7}{8}\) x \(\dfrac{4}{7}\) +\(\dfrac{5}{9}\)
D,\(\dfrac{9}{8}:\dfrac{4}{3}-\dfrac{4}{7}\)
8/9 x 5/4 + 3/5 = 10/9 + 3/5 = 77/45
5/8 + 1/4 = 5/9 + 2/8 = 7/8
1/2 + 5/9 = 9/18 + 5/9 = 14/9
9/8 x 3/4 - 4/7 = 27/32 - 4/7 = 61/224
a) \(\dfrac{8}{9}:\dfrac{4}{5}+\dfrac{3}{5}=\dfrac{8}{9}\times\dfrac{5}{4}+\dfrac{2}{5}=\dfrac{10}{9}+\dfrac{2}{5}=\dfrac{50}{45}+\dfrac{18}{45}=\dfrac{68}{45}\)
b) \(\dfrac{5}{8}+\dfrac{1}{4}=\dfrac{5}{8}+\dfrac{2}{8}=\dfrac{6}{8}=\dfrac{3}{4}\)
c) \(\dfrac{7}{8}\times\dfrac{4}{7}+\dfrac{5}{9}=\dfrac{1}{2}+\dfrac{5}{9}=\dfrac{9}{18}+\dfrac{10}{18}=\dfrac{19}{18}\)
d) \(\dfrac{9}{8}:\dfrac{4}{3}-\dfrac{4}{7}=\dfrac{9}{8}\times\dfrac{3}{4}-\dfrac{4}{7}=\dfrac{27}{32}-\dfrac{4}{7}=\dfrac{61}{244}\)
A=8/9x5/4+3/5
=40/36+3/5
=10/9+3/5
=50/45+27/45=77/45
B=5/8+2/8=7/8
C=1/2+5/9
=9/18+10/18=19/18