0,5 x-2/3 x bang 5/12
a,3/4 . (-5/12)+3/4.(-7/12)
2. tìm x
a, 2/3 .x-0,5=3/4
b,3/x-2=-2/x-4 (đk x khác 2;x khác 4)
a,3/4 . (-5/12)+3/4.(-7/12)
` 3/4 . [ - ( 5/12 + 7/12 ) ] `
`3/4 . (-1) = -3/4 `
`2/3 . x - 0,5 = 3/4 `
` x - 0,5 = 3/4 - 2/3 `
` x-0,5 = 1/12 `
` x = 1/12 + 0,5 `
` x= 7/12 `
a, 3/4 . (-5/12)+3/4.(-7/12)
= 3/4 . [(-5/12) + (-7/12)]
= 3/4 . (-1)
= -3/4
----------------------------------------------------------------------------
a, 2/3 .x-0,5=3/4
2/3 . x = 3/2 + 0,5
2/3 . x = 2
x = 2 : 2/3
x = 3
vậy x = 3
a,3/4 . (-5/12)+3/4.(-7/12)
2. tìm x
a, 2/3 .x-0,5=3/4
b,3/x-2=-2/x-4 (đk x khác 2;x khác 4)
Bài 2:
a: =>2/3x=3/4+1/2=3/4+2/4=5/4
=>x=5/4:2/3=5/4*3/2=15/8
b:=>-2x+4=3x-12
=>-5x=-16
=>x=16/5
Tìm x :
0,5.x - 2/3.x=5/12
0,5.x-2/3.x=5/12
(0,5-2/3).x =5/12
(-1/6).x =5/12
x =5/12:(-1/6)
x =-5/2
Vậy x=-5/2
Tim x:
a, [x+1] + [x+2] + [x+3] + ... + [x+100] bang 206050
b, [1-3/10-x] : [19/20-1-2/5]
c, |2x-2| bang x+18
d, | |11-x| +9| - 7 bang 12
\(0,5.x-\dfrac{2}{3}.x=\dfrac{5}{12}\)
Pt \(\Leftrightarrow\dfrac{1}{2}x-\dfrac{2}{3}x=\dfrac{5}{12}\)
\(\Leftrightarrow x\left(\dfrac{1}{2}-\dfrac{2}{3}\right)=\dfrac{5}{12}\)
\(\Leftrightarrow-\dfrac{1}{6}.x=\dfrac{5}{12}\)
\(\Leftrightarrow x=-\dfrac{5}{2}\)
0,5.x-\(\dfrac{2}{3}\).x=\(\dfrac{5}{12}\)
\(\Leftrightarrow\)\(\dfrac{1}{2}\).x-\(\dfrac{2}{3}\).x=\(\dfrac{5}{12}\)
\(\Leftrightarrow\)x.(\(\dfrac{1}{2}\)-\(\dfrac{2}{3}\))=\(\dfrac{5}{12}\)
\(\Leftrightarrow\)x.\(\dfrac{-1}{6}\) =\(\dfrac{5}{12}\)
\(\Leftrightarrow\)x =\(\dfrac{5}{12}\):\(\dfrac{-1}{6}\)
\(\Leftrightarrow\)x =\(\dfrac{5}{12}\).\(\dfrac{-6}{1}\)
\(\Leftrightarrow\)x = \(\dfrac{-5}{2}\)
Tinh bang cahc thuan tien
5 x 12 x 3 x 7 / 3x8x7x5
2 x 5 x 4 x 6 / 4 x 3 x 5 x 7 =
5 x 12 x 3 x 7 / 3 x 8 x 7 x 5 = 3/2
2 x 5 x 4 x 6 / 4 x 3 x 5 x 7 = 4/7
5 x 12 x 3 x 7 / 3 x 8 x 7 x 5
=5 x 3 x 7 x 12/ 3 x 7 x 5 x 8
= 12/8 = 3/2
2 x 5 x 4 x 6 / 4 x 3 x 5 x 7
=4/7
\(\frac{5.12.3.7}{3.8.7.5}=\frac{12}{8}=\frac{3}{2}\\ \)
2) \(\frac{2.5.4.6}{4.3.5.7}=\frac{12}{21}=\frac{4}{7}\)
Tim 2 so co tich bang 6 tong bang 5
Tinh x:4+3=7
Tnh 18_6÷x=12
2/2/3:x=1/7/9:0,02
-3/5:3/14+0,5.x=12
2^2x+1=2^3.2^4
|3-x|+1/2=5
\(2\frac{2}{3}:x=1\frac{8}{9}:0,02\)
\(\frac{8}{3}:x=\frac{17}{9}:\frac{1}{50}\)
\(\frac{8}{3}:x=\frac{17}{9}.50\)
\(\frac{8}{3}:x=\frac{850}{9}\)
\(x=\frac{8}{3}:\frac{850}{9}\)
\(x=\frac{8}{3}x\frac{9}{850}\)
\(x=\frac{12}{425}\)
Vậy \(x=\frac{12}{425}\)
\(-\frac{3}{5}:\frac{3}{14}+0,5.x=12\)
\(-\frac{3}{5}:\frac{3}{14}+\frac{1}{2}.x=12\)\(-\frac{3}{5}x\frac{14}{3}+\frac{1}{2}.x=12\)\(-\frac{14}{5}+\frac{1}{2}.x=12\)\(\frac{1}{2}.x=12-\left(-\frac{14}{5}\right)\)\(\frac{1}{2}.x=12+\frac{14}{5}\)\(\frac{1}{2}.x=\frac{60}{5}+\frac{14}{5}\)\(\frac{1}{2}.x=\frac{74}{5}\) \(x=\frac{74}{5}:\frac{1}{2}\) \(x=\frac{74}{5}x2\) \(x=\frac{158}{5}\) Vậy \(x=\frac{158}{5}\)Tìm x, biết:
a) x+\(\dfrac{1}{6}\)=\(\dfrac{-3}{8}\) b) \(2-\left(\dfrac{3}{4}-x\right)=\dfrac{7}{12}\)
c) \(\dfrac{1}{2}x\)+\(\dfrac{1}{8}x=\dfrac{3}{4}\) d) 75%-\(1\dfrac{1}{2}+0,5:\dfrac{5}{12}-\left(\dfrac{-1}{2}\right)^2\)
\(a.x+\dfrac{1}{6}=-\dfrac{3}{8}\)
\(\Leftrightarrow x=-\dfrac{13}{24}\)
\(b.2-\left(\dfrac{3}{4}-x\right)=\dfrac{7}{12}\)
\(\Leftrightarrow2-\dfrac{3}{4}+x=\dfrac{7}{12}\)
\(\Leftrightarrow x=-\dfrac{2}{3}\)
\(c.\dfrac{1}{2}x+\dfrac{1}{8}x=\dfrac{3}{4}\)
\(\Leftrightarrow\dfrac{5}{8}x=\dfrac{3}{4}\)
\(\Leftrightarrow x=\dfrac{6}{5}\)
\(d.75\%-1\dfrac{1}{2}+0,5:\dfrac{5}{12}-\left(\dfrac{-1}{2}\right)^2\)
\(=\dfrac{75}{100}-\dfrac{3}{2}+\dfrac{1}{2}:\dfrac{5}{12}-\dfrac{1}{4}\)
\(=-\dfrac{3}{4}+\dfrac{6}{5}-\dfrac{1}{4}\)
\(=\dfrac{1}{5}\)
a) \(x+\dfrac{1}{6}=\dfrac{-3}{8}\)
\(x=\dfrac{-3}{8}-\dfrac{1}{6}\)
\(x=\dfrac{-13}{24}\)
vậy x =....
b) \(2-\left(\dfrac{3}{4}-x\right)=\dfrac{7}{12}\)
\(\dfrac{3}{4}-x=2-\dfrac{7}{12}\)
\(\dfrac{3}{4}-x=\dfrac{17}{12}\)
\(x=\dfrac{3}{4}-\dfrac{17}{12}\)
\(x=\dfrac{-2}{3}\)
vậy x =....