Tìm x
x-3/x+5=5/7
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Bài 1:
a: x/-2=-18/x
=>x2=36
=>x=6 hoặc x=-6
b: x/2+x/5=17/10
=>7/10x=17/10
hay x=17/7
`x xx 6/7=5/14`
`=>x=5/14:6/7`
`=>x=5/14xx7/6`
`=>x=35/84`
`=>x=5/12`
Vậy `x=5/12`
__
`x:2/3=4/9`
`=>x=4/9xx2/3`
`=>x=8/27`
Vậy `x=8/27`
__
`x-1/4=3/2`
`=>x=3/2+1/4`
`=>x=6/4+1/4`
`=>x=7/4`
Vậy `x=7/4`
__
`x+4/5=8/9`
`=>x=8/9-4/5`
`=>x=40/45-36/45`
`=>x=4/45`
Vậy `x=4/45`
\(x\cdot\dfrac{6}{7}=\dfrac{5}{14}\)
\(x\) \(=\dfrac{5}{14}:\dfrac{6}{7}\)
\(x\) \(=\dfrac{5}{12}\)
\(x:\dfrac{2}{3}=\dfrac{4}{9}\)
\(x\) \(=\dfrac{4}{9}\cdot\dfrac{2}{3}\)
\(x\) \(=\dfrac{8}{27}\)
\(x-\dfrac{1}{4}=\dfrac{3}{2}\)
\(x\) \(=\dfrac{3}{2}+\dfrac{1}{4}\)
\(x\) \(=\dfrac{7}{4}\)
\(x+\dfrac{4}{5}=\dfrac{8}{9}\)
\(x\) \(=\dfrac{8}{9}-\dfrac{4}{5}\)
\(x\) \(=\dfrac{4}{45}\)
a, \(x + 1/6 = -3/8 \)
\(x = -3/8 - 1/6\)
\(x = -13/24\)
Vậy \(x = -13/24\)
b, \(-3/7 - x = 4/5 - 2/3\)
\(-3/7 - x = 2/15\)
\(x = -3/7 - 2/15\)
\(x = -59/105.\)
Vậy \(x = -59/105\)
x+1/6=-3/8
x=-3/8-1/6
x=-13/24
-3/7-x=4/5+-2/3
-3/7-x=2/15
x=-3/7-2/15
x=-59/105
x*3,4=15,3
x = 15,3 : 3,4
x = 4,5
7,5:x=0,24
x = 7,5 : 0,24
x = 31,25
5/6:x=7/8
x = 5/6 : 7/8
x = 20/21
2/3*x=5/9
x = 5/9 : 2/3
x = 5/6
Xx3,4=15,3
X = 15,3 : 3,4
X =4.5
7,5:x=0,24
x=7,5 : 0,24
x= 31.25
5/6:x=7/8
x=5/6 : 7/8
x= 20/21
2/3xX=5/9
X= 5/9 : 2/3
X= 5/6
A) X = 5/8 - 1/4
B) X = 1/10 + 3/5
C) X = 6/11 : 2/7
D) X = 1/4 x 3/2
Còn đâu bạn tự tính nha
Nhớ tích tích đúng cho mình đấy
a)x=5/8-1/4
x=5/8-2/8
x=3/8
b)x=1/10+3/5
x=1/10+3/10
x=4//10
c)x=2/11:2/7
x=2/11x7/2
x=11/7
d)x=1/4x3/2
x=3/8
đánh giá 5 sao cho mình nhá! cảm ơn nhìu
Bài 1:
Ta có: \(x-35\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow65\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow x=\dfrac{1}{25}:\dfrac{13}{20}=\dfrac{1}{25}\cdot\dfrac{20}{13}=\dfrac{4}{65}\)
Vậy: \(x=\dfrac{4}{65}\)
Bài 2:
a) Ta có: \(17\dfrac{2}{31}-\left(\dfrac{15}{17}+6\dfrac{2}{31}\right)\)
\(=17\dfrac{2}{31}-\dfrac{15}{17}-6\dfrac{2}{31}\)
\(=11+\dfrac{2}{31}-\dfrac{15}{17}\)
\(=\dfrac{5366}{527}\)
Giải:
\(\dfrac{1}{3.5}+\dfrac{1}{5.7}+\dfrac{1}{7.9}+...+\dfrac{1}{x.\left(x+2\right)}=\dfrac{16}{99}\)
\(\dfrac{1}{2}.\left(\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9}+...+\dfrac{2}{x.\left(x+2\right)}\right)=\dfrac{16}{99}\)
\(\dfrac{1}{2}.\left(\dfrac{1}{2}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+...+\dfrac{1}{x}-\dfrac{1}{x+2}\right)=\dfrac{16}{99}\)
\(\dfrac{1}{2}.\left(\dfrac{1}{3}-\dfrac{1}{x+2}\right)=\dfrac{16}{99}\)
\(\dfrac{1}{3}-\dfrac{1}{x+2}=\dfrac{16}{99}:\dfrac{1}{2}\)
\(\dfrac{1}{3}-\dfrac{1}{x+2}=\dfrac{32}{99}\)
\(\dfrac{1}{x+2}=\dfrac{1}{3}-\dfrac{32}{99}\)
\(\dfrac{1}{x+2}=\dfrac{1}{99}\)
\(\Rightarrow x+2=99\)
\(x=99-2\)
\(x=97\)
Chúc em học tốt!
\(\dfrac{1}{3x5}+\dfrac{1}{5x7}+\dfrac{1}{7x9}+...+\dfrac{1}{x\left(x+2\right)}=\dfrac{16}{99}\)
\(=\dfrac{1}{2}\left(\dfrac{2}{3x5}+\dfrac{2}{5x7}+...+\dfrac{2}{x\left(x+2\right)}\right)=\dfrac{16}{99}\)
\(=\dfrac{2}{3x5}\)\(+\dfrac{2}{5x7}+...+\dfrac{2}{x\left(x+2\right)}=\dfrac{32}{99}\)
\(=\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}+.....+\dfrac{1}{x}-\dfrac{1}{x+2}=\dfrac{32}{99}\)
\(=\dfrac{1}{3}-\dfrac{1}{x+2}=\dfrac{32}{99}=>x=97\)
x-3/x+5=5/7
=>7(x-3)=5(x+5)
=>7x-21=5x+25
=>7x-5x=21+25
=>2x=46
=>x=23
Vậy...
Chúc bạn học tốt nha!!!! Hwaitting!
x-3/x =-30/7
suy ra x-3 = -30/7 x
x +30/7x=3
37/7 x = 3
x =21/37
Vậy x =21/37 là giá trị cần tìm