60% . x+2/3x=1/3.6 1/3
60%x+2/3x=1/3.6 1/3
Tìm x,y biết:
a) 3.(x-1/2)-5(x+3/5)=-x+1/5
b) 3.(3x-1/2)^3 +1/9=0
c) 60%x+2/3x=1/3.6/1/3
d)x/2=-3y/4 và x-2y=3
e) 2x/5=3y/7 và 2x-y=5
Tìm x, biết
a,(2x-4,5)x1 4/7=-11/14
b,|x/7|+6\24
c,60%x+2/3x+1/3.6 1/3
d,|2x-1/3|+5/6=1
60%.X+2/3=1/3.6+1/3
Ta có:
\(60\%X+\dfrac{2}{3}=\dfrac{1}{3}.6+\dfrac{1}{3}\\ < =>60\%X=\dfrac{1}{3}.6+\dfrac{1}{3}-\dfrac{2}{3}\\ < =>60\%X=2+\dfrac{1}{3}-\dfrac{2}{3}\\ < =>60\%X=\dfrac{5}{3}\\ =>X=\dfrac{5}{3}:60\%=\dfrac{25}{9}\)
Vậy: X có giá trị bằng 25/9
tìm các số x,y biết
a,60%x+2/3x=1/3.6 1/3 b,[-0,6x-1/2].3/4-(-1)=1/3
c,2[1/2x-1/3]-3/2=1/4 d,tìm một số biết 2/3 của nó bằng 720%
a) \(60\%x+\frac{2}{3}x=\frac{1}{3}.6\frac{1}{3}\)
=> \(\frac{3}{5}x+\frac{2}{3}x=\frac{19}{9}\)
=> \(\frac{19}{15}x=\frac{19}{9}\)
=> \(x=\frac{19}{9}:\frac{19}{15}\)
=> \(x=\frac{5}{3}\)
b) (-0,6x - 1/3) . 3/5 - (-1) = 1/3
=> (-3/5x - 1/3) .3/5 = 1/3 - 1
=> (-3/5x - 1/3).3/5 = -2/3
=> -3/5x - 1/3 = -2/3 : 3/5
=> -3/5x - 1/3 = -10/9
=> -3/5x = -10/9 + 1/3
=> -3/5x = -7/9
=> x = -7/9 : (-3/5)
=> x = 35/27
a,60%x+2/3x=1/3.6 1/3
x(60%+2/3)=19/6
x.19/15=19/6
x=19/6 : 19/15
x=5/2
b,[-0,6x-1/2].3/4-(-1)=1/3
(-3/5x-1/2).3/4=1/3-1
(-3/5x-1/2).3/4=-2/3
-0,6x-0,5=-2/3:3/4
................................
c,2[1/2x-1/3]-3/2=1/4
....................................... (tương tự...)
d,Số đó là:720% : 2/3=10,8
c) 2(1/2x - 1/3) - 3/2 = 1/4
=> 2(1/2x - 1/3) = 1/4 + 3/2
=> 2(1/2x - 1/3) = 7/4
=> 1/2x - 1/3 = 7/4 : 2
=> 1/2x - 1/3 = 7/8
=> 1/2x = 7/8 + 1/3
=> 1/2x = 29/24
=> x = 29/24 : 1/2
=> x = 29/12
d) Số đó là : 720% : 2/3 = 54/5
1. Tình giá trị các biểu thức 1 cách hợp lí
A= ( 1/2 - 1) x (1/3 - 1) x (1/4 -1) ........ (1/1012 - 1)
B= 162. ( 1/3 - 1/5 + 1/7 trên 5/3 - 1 + 5/7 ) + ( 1 + 4/5 - 2/3 trên 5/4 + 1 - 5/6) x 818181/797979
2. Tìm x biết
a/ ( x + 3 ) / 5 = 5/7
b. // x - 5 / -4 / = 5
c/ ( -4/3 ) 3x + 1 = 256/81
d/ 3x2 - 133 : 338 = 0,25
e/ ( 0,4x - 2 ) - ( 1,5x = 1 ) + ( 4x + 0.8 ) = 3.6
Bài 2:
a: (x+3)/5=5/7
=>x+3=25/7
hay x=4/7
b: ||x-5|-4|=5
=>|x-5|-4=5 hoặc |x-5|-4=-5
=>|x-5|=9
=>x-5=9 hoặc x-5=-9
=>x=14 hoặc x=-4
c: \(\left(-\dfrac{4}{3}\right)^{3x+1}=\dfrac{256}{81}\)
nên 3x+1=4
=>3x=3
hay x=1
Tìm x
1) -5(x + 1/5) - 1/2(x -2/3) = 3/2x - 5/6
2) 3(x - 1/2) - 5(x + 3/5) = -x + 1/5
3) 3(3x - 1/2)3 + 1/9 = 0
4) 60% .x + 2/3x =1/3 . 6/1/3
\(-5\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)
\(\Leftrightarrow-5x-\frac{1}{5}-\frac{1}{2}x+\frac{1}{3}=\frac{3}{2}x-\frac{5}{6}\)
\(\Leftrightarrow\left(-5x-\frac{1}{2}x\right)+\left(\frac{1}{3}-\frac{1}{5}\right)=\frac{3}{2}x-\frac{5}{6}\)
\(\Leftrightarrow\left(\frac{-10}{2}x-\frac{1}{2}x\right)+\left(\frac{5}{15}-\frac{3}{15}\right)=\frac{3}{2}x-\frac{5}{6}\)
\(\Leftrightarrow\frac{-11}{2}x+\frac{2}{15}=\frac{3}{2}x-\frac{5}{6}\)
\(\Leftrightarrow\frac{-11}{2}x-\frac{3}{2}x=-\frac{5}{6}-\frac{2}{15}\)
\(\Leftrightarrow\frac{-14}{2}x=-\frac{25}{30}-\frac{4}{30}\)
\(\Leftrightarrow-7x=-\frac{29}{30}\)
\(\Leftrightarrow x=-\frac{29}{30}\times\frac{-1}{7}\)
\(\Leftrightarrow x=\frac{29}{210}\)
\(3\left(x-\frac{1}{2}\right)-5\left(x+\frac{3}{5}\right)=-x+\frac{1}{5}\)
\(\Leftrightarrow3x-\frac{3}{2}-5x-3=\frac{1}{5}-x\)
\(\Leftrightarrow\left(3x-5x\right)-\left(\frac{3}{2}+3\right)=\frac{1}{5}-x\)
\(\Leftrightarrow-2x-\left(\frac{3}{2}+\frac{6}{2}\right)=\frac{1}{5}-x\)
\(\Leftrightarrow-2x-\frac{9}{2}=\frac{1}{5}-x\)
\(\Leftrightarrow-2x+x=\frac{1}{5}+\frac{9}{2}\)
\(\Leftrightarrow-x=\frac{2}{10}+\frac{45}{10}\)
\(\Leftrightarrow-x=\frac{47}{10}\)
\(\Leftrightarrow x=\frac{-47}{10}\)
\(3\left(3x-\frac{1}{2}\right)^3+\frac{1}{9}=0\)
\(\Leftrightarrow3\left(3x-\frac{1}{2}\right)^3=0-\frac{1}{9}\)
\(\Leftrightarrow3\left(3x-\frac{1}{2}\right)^3=\frac{-1}{9}\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=\frac{-1}{9}\div3\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=\frac{-1}{9}\times\frac{1}{3}\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=\frac{-1}{27}\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=\left(\frac{-1}{3}\right)^3\)
\(\Leftrightarrow3x-\frac{1}{2}=\frac{-1}{3}\)
\(\Leftrightarrow3x=\frac{-1}{3}+\frac{1}{2}\)
\(\Leftrightarrow3x=\frac{-2}{6}+\frac{3}{6}\)
\(\Leftrightarrow3x=\frac{1}{6}\)
\(\Leftrightarrow x=\frac{1}{6}\div3\)
\(\Leftrightarrow x=\frac{1}{6}\times\frac{1}{3}\)
\(\Leftrightarrow x=\frac{1}{18}\)
60%x+2/3x=1/3 . 6/1/3
Tìm x
a) 1/3x + 2/5( x - 1 ) = 0
b) (2x - 3 )(6 - 2x ) =0
c) 2|1/2x - 1/3 | - 3/2 = 1/4
d) 3/4 - 2 . | 2x - 2/3 | = 2
e) ( 3x - 1)(-1/2x + 5 ) = 0
g)-5(x + 1/5 ) - 1/2(x - 2/3 ) = 2/3x - 5/6
h) 3(x - 1/2 ) - 5(x + 3/5 ) = -3 + 1/5
i) 60%x + 2/3x = 1/3. 6và1/3 ( 6và1/3 là hỗn số )