0.5+1/+0.4+5/7+1/6-4/35
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(0,5+\frac{1}{3}+0,4+\frac{5}{7}+\frac{1}{6}-\frac{4}{35}\)
\(=\left(\frac{1}{2}+\frac{1}{3}+\frac{2}{5}+\frac{1}{6}\right)+\left(\frac{5}{7}-\frac{4}{35}\right)\)
\(=\frac{15+10+12+5}{30}+\frac{25-4}{35}\)
\(=\frac{7}{5}+\frac{3}{5}\)
\(=2\)
a. 2/3+ -1/6
=4/6+ -1/6 = 1/2
b.5/4 - 3/16
=20/16-3/16 = 17/16
c.1/2+ (4/5 - 1/2)
= 1/2+ 4/5 -1/2= 1/2- 1/2 +4/5
=0+4/5= 4/5
d. (0.5-3/4) . (1/5 - 0.4)
= (1/2- 3/4) . (1/5-2/5)
=(2/4 - 3/4) . (1/5 - 2/5)
= 1/4 . 1/5= 1/20
e. 3/5 . 7/13 - 3/5. 18/13
= 3/5. (7/13 - 18/13)
= 3/5. -11/13= -33/65
#hoctot
`a)2/3+ -1/6=(2xx2)/(3xx2)+ -1/6=4/6+ -1/6=1/2`
`b)5/4-3/16=20/16-3/16=17/16`
`c)1/2+(4/5-1/2)=1/2+4/5-1/2=1/2-1/2+4/5=0/4+4/5=4/5`
`d)(0,5-3/4)xx(1/5xx0,4)=(1/2-3/4)xx(1/5-2/5)=(2/4-3/4)xx(1/5-2/5)=-1/4xx-1/5=1/20`
`e)3/5xx7/13-3/5xx18/13`
`=3/5xx(7/13-18/13)`
`=3/5xx11/13`
`=33/65`
$#Lani2011$
Chức bn học tốt
\(a,\frac{3}{35}-\left[\frac{3}{5}+x\right]=\frac{2}{7}\)
\(\Rightarrow\frac{3}{5}+x=\frac{3}{35}-\frac{2}{7}\)
\(\Rightarrow\frac{3}{5}+x=\frac{3}{35}-\frac{2\cdot5}{35}\)
\(\Rightarrow\frac{3}{5}+x=\frac{3}{35}-\frac{10}{35}=\frac{-7}{35}\)
\(\Rightarrow x=\frac{-7}{35}-\frac{3}{5}=\frac{-7}{35}-\frac{3\cdot7}{35}=\frac{-7}{35}-\frac{21}{35}=\frac{-28}{35}=\frac{-4}{5}\)
\(b,\frac{5}{6}+\frac{1}{6}:x=\frac{3}{4}\)
\(\Rightarrow\frac{1}{6}:x=\frac{3}{4}-\frac{5}{6}\)
\(\Rightarrow\frac{1}{6}:x=\frac{18}{24}-\frac{20}{24}\)
\(\Rightarrow\frac{1}{6}:x=\frac{-2}{24}\)
\(\Rightarrow x=\frac{1}{6}:\frac{-2}{24}=\frac{1}{6}:\frac{-1}{12}=\frac{12}{-6}=\frac{-12}{6}=-2\)
\(c,\left|x-3\frac{4}{7}\right|=-0,5\)
Vì \(\left|x-3\frac{4}{7}\right|\ge0\)mà \(-0,5< 0\)nên \(x\in\varnothing\)
Vậy không có giá trị x thỏa mãn
a) 3/35-(3/5+x)=2/7
<=> 3/5+x=3/35-2/7
<=> 3/5+x=3/35-10/35
<=> 3/5+x=-7/35
<=> 3/5+x=-1/5
<=> x=-1/5-3/5
<=> x=-4/5
Vậy x=-4/5
\(A=\dfrac{\dfrac{2}{4}-\dfrac{2}{5}+\dfrac{2}{7}+\dfrac{2}{13}}{\dfrac{17}{4}-\dfrac{17}{5}+\dfrac{17}{7}+\dfrac{17}{13}}=\dfrac{2}{17}\)
\(D=\left(\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{97.99}\right)-\left(\frac{1}{2.4}+\frac{1}{4.6}+...+\frac{1}{98.100}\right)\)
Làm tắt nha :
\(D=\frac{1}{2}\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{97}-\frac{1}{99}\right)-\frac{1}{2}\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{98}-\frac{1}{100}\right)\)
\(D=\frac{1}{2}\left(\frac{1}{1}-\frac{1}{99}\right)-\frac{1}{2}\left(\frac{1}{2}-\frac{1}{100}\right)\)
\(D=\frac{1}{2}.\frac{98}{99}-\frac{1}{2}.\frac{98}{100}\)
\(D=\frac{1}{2}\left(\frac{98}{99}-\frac{98}{100}\right)\)
Tự tính nốt nha