tìm x biết:................
x/3-1/2=1/5
1. Tìm X, biết: x - \(\dfrac{2}{3}\) x ( X + 9 ) = 1
2. Tìm X, biết: X - \(\dfrac{11}{15}\) = \(\dfrac{3+X}{5}\)
\(1.x-\dfrac{2}{3}\times\left(x+9\right)=1\)
\(x-\dfrac{2}{3}\times x-6=1\)
\(x\times\left(1-\dfrac{2}{3}\right)=7\)
\(x\times\dfrac{1}{3}=7\)
\(x=21\)
\(2.x-\dfrac{11}{15}=\dfrac{3+x}{5}\)
\(\dfrac{15x}{15}-\dfrac{11}{15}=\dfrac{9+3x}{15}\)
\(15x-11=9+3x\)
\(12x=20\)
\(x=\dfrac{5}{3}\)
Tìm x, biết :
a. 1/2 + x = 3/4
b. 5/2 - x = 1/3
c. 2. ( 1/3 + x ) = 1/5
d. 2/3 - ( 1/2 - x ) = 1/5
`a, 1/2 +x=3/4`
`=> x= 3/4 -1/2`
`=> x= 3/4-2/4`
`=>x= 1/4`
`b, 5/2 -x=1/3`
`=> x= 5/2 -1/3`
`=> x= 15/6 - 2/6`
`=>x= 13/6`
`c, 2 . (1/3 +x)=1/5`
`=> 1/3 +x=1/5:2`
`=> 1/3 +x= 1/10`
`=>x= 1/10-1/3`
`=>x= 3/30 - 10/30`
`=>x=-7/30`
`d, 2/3 - (1/2 -x)=1/5`
`=> 1/2-x= 2/3 -1/5`
`=>1/2-x= 10/15 - 3/15`
`=>1/2-x=7/15`
`=>x= 1/2-7/15`
`=>x=1/30`
`1/2 + x = 3/4`
`=> x = 3/4 - 1/2`
`=> x = 1/4`
`5/2 - x = 1/3`
`=> x = 5/2 - 1/3`
`=> x = 13/6`
`2.(1/3 + x) = 1/5`
`=>1/3 + x = 1/10 `
`=> x = 1/10 - 1/3`
`=> x = -7/30`
`2/3 - (1/2 -x)= 1/5`
`=> 1/2 - x = 7/15`
`=> x = 1/2 - 7/15`
`=> x = 1/30`
a. \(\dfrac{1}{2}+x=\dfrac{3}{4}\)
⇔ \(x=\dfrac{3}{4}-\dfrac{1}{2}\)
⇔ \(x=\dfrac{1}{4}\)
b. \(\dfrac{5}{2}-x=\dfrac{1}{3}\)
⇔ \(-x=\dfrac{1}{3}-\dfrac{5}{2}\)
⇔ \(-x=-\dfrac{13}{6}\)
⇔ \(x=\dfrac{13}{6}\)
c. \(2\left(\dfrac{1}{3}+x\right)=\dfrac{1}{5}\)
⇔ \(\dfrac{1}{3}+x=\dfrac{1}{5}\div2\)
⇔ \(x=\dfrac{1}{10}-\dfrac{1}{3}\)
⇔ \(-\dfrac{7}{30}\)
d. \(\dfrac{2}{3}-\left(\dfrac{1}{2}-x\right)=\dfrac{1}{5}\)
⇔ \(-\dfrac{1}{2}+x=\dfrac{1}{5}-\dfrac{2}{3}\)
⇔ \(x=-\dfrac{7}{15}+\dfrac{1}{2}\)
⇔ \(x=\dfrac{1}{30}\)
Tìm x biết
-5(x+1/5)-1/2(x-2/3)=3/2x-5/6
3(x-1/2)-5(x+3/5)=-x+1/5
Bài 1 : Tìm x ,y,z biết:
a, 3/x-1 = 4/y-2 = 5/z-3 và x+y+z = 18
b, 3/x-1 = 4/y-2 = 5/z-3 và x.y.z = 192
Bài 2 : Tìm x,y,z biết : x^3+y^3/6 = x^3-2y^3/4 và x^6.y^6 = 64
Bài 3 : Tìm x,y,z biết :x+4/6 = 3y-1/8 = 3y-x-5/x
Bài 4 :Tìm x,y,z biết : x+y+2005/z = y+z-2006 = z+x+1/y = 2/x+y+z
bài 1 : a,ta có 3/x-1 =4/y-2=5/z-3 => x-1/3=y-2/4=z-3/5
áp dụng .... => x-1+y-2+z-3 / 3+4+5 = x+y+z-1-2-3/3+4+5 = 12/12=1
do x-1/3 = 1 => x-1 = 3 => x= 4 ( tìm y,z tương tự
Bài 1:
a) Ta có: 3/x - 1 = 4/y - 2 = 5/z - 3 => x - 1/3 = y - 2/4 = z - 3/5 áp dụng ... =>x - 1 + y - 2 + z - 3/3 + 4 + 5 = x + y + z - 1 - 2 - 3/3 + 4 + 5 = 12/12 = 1 do x - 1/3 = 1 => x - 1 = 3 => x = 4 ( tìm y, z tương tự )
bài 1 :tìm x , biết :
(x-7)^ x+1(x-7)^x+11=0
bài 2 :tìm x , biết :
a,|2x-3| > 5 c,|3x-1| ≤ 7 d,|3x-5| + |2x+3| = 7
bài 3 :
a,tính tổng S = 1 + 5^2 + 5^4 + ....... + 5^200.
b,so sánh 2^30 + 3^30 + 4^30 và 3.24^10
Bài 1 : Tìm x biết :
a) 5|x-1| + |x-2| = |12-3x|
b) 12x+7 - 3|x-3| = 5|x+1|
Bài 2 : Tìm x biết :
a) |x-3| < 2
b) 2|x-1| - 5(2-x) > 2
c) 4|x-1| - 7|2-4x| < 5
d) 3(2-3x) + |x-3| - 2|1-x| > 3
giải chi tiết ra giúp mk nhé, cảm ơn nhiều
Tìm x,biết:
a)-5×(x+1/5)-1/2×(x-2/3)=3/2x-5/6
b)3×(x-1/2)-5(x+3/5)=-x+1/5
bài 1 : tìm x biết
a, ( x - 2 ) : 2 x 3 = 6
b, X : ( hỗn số 3 1/2 x hỗn số 2 2/3 ) = 9/56
c, 1 + 3 + 5 + .....+ ( 2 x X + 1 ) = 625
bài 2 : tìm x biết
a, ( x - 1/2 ) x 5/3 = 7/4 - 1/2
b, 5 x X + X = 42
c, ( x+1 ) + ( x+ 3 ) + ( x + 5 ) + ....+ ( x + 11 ) = 58
bài 3 tìm x biết
a, X - 1,25 x 4 = 7,5
b, X = ( hỗn số 6 3/5 : 6 - 0 , 125 x 8 + hỗn số 2 2/15 x 0,03 ) x 2/11
c, ( X + 1 ) +(X + 2 ) + ( X + 3 ) + ....+(X + 20 ) = 750
1
\(\left(x-2\right):2.3=6\)
\(\Leftrightarrow\left(x-2\right):2=2\)
\(\Leftrightarrow\left(x-2\right)=4\)
\(\Leftrightarrow x=4+2=6\)
c) ta có
\(\left[\left(2x+1\right)+1\right]m:2=625\)
\(\Leftrightarrow\left[\left(2x+1\right)+1\right]\left\{\left[\left(2x+1\right)-1\right]:2+1\right\}=1250\)
\(\Leftrightarrow\left(2x+1\right)^2+1-1:2+1=1250\)
\(\Leftrightarrow\left(2x+1\right)^2+1-2+1=1250\)
\(\Leftrightarrow\left(2x+1\right)^2+1-2=1249\)
\(\Leftrightarrow\left(2x+1\right)^2+1=1251\)
\(\Leftrightarrow\left(2x+1\right)^2=1250\)
...
2
\(\left(x-\frac{1}{2}\right).\frac{5}{3}=\frac{7}{4}-\frac{1}{2}\)
\(\Leftrightarrow\left(x-\frac{1}{2}\right).\frac{5}{3}=\frac{5}{4}\)
\(\Leftrightarrow\left(x-\frac{1}{2}\right)=\frac{5}{4}:\frac{5}{3}\)
\(\Leftrightarrow\left(x-\frac{1}{2}\right)=\frac{5}{4}.\frac{3}{5}\)
\(\Leftrightarrow x-\frac{1}{2}=\frac{3}{4}\)
\(\Leftrightarrow x=\frac{3}{4}+\frac{1}{2}=\frac{5}{4}\)
Tìm x biết -5.[x+(1/5)]-(1/2).[x-(2/3)]=(3/2).x-(5/6)