1/4xX+X+X+21,4=31,6
Tìm X:
4xX/1x5+4xX/5x9+4xX/9x13+4xX/13x17=16
\(\dfrac{4\times x}{1\times5}\) + \(\dfrac{4\times x}{5\times9}\) + \(\dfrac{4\times x}{9\times13}\) + \(\dfrac{4\times x}{13\times17}\) = 16
\(x\times\left(\dfrac{4}{1\times5}+\dfrac{4}{5\times9}+\dfrac{4}{9\times13}+\dfrac{4}{13\times17}\right)\) = 16
\(x\) \(\times\) (\(\dfrac{1}{1}\) - \(\dfrac{1}{5}\) + \(\dfrac{1}{5}\) - \(\dfrac{1}{9}\) + \(\dfrac{1}{9}\) - \(\dfrac{1}{13}\) + \(\dfrac{1}{13}\) - \(\dfrac{1}{17}\)) = 16
\(x\) \(\times\) ( \(\dfrac{1}{1}\) - \(\dfrac{1}{17}\)) = 16
\(x\) \(\times\) \(\dfrac{16}{17}\) = 16
\(x\) = 16 : \(\dfrac{16}{17}\)
\(x\) = 17
Tìm x
1/4xX-(x-4/5)-1/2=2x-6
1/4 . x - (x - 4/5) - 1/2 = 2x - 6
1/4 x - x + 4/5 - 1/2 = 2x - 6
1/4 x - x - 2x = -6 - 4/5 + 1/2
-11/4 x = -63/10
x = -63/10 : (-11/4)
x = 126/55
3/8 x X+1/4xX=2/5
\(\frac{3}{8}\times x+\frac{1}{4}\times x=\frac{2}{5}\)
\(\Rightarrow x\times\left(\frac{3}{8}+\frac{1}{4}\right)=\frac{2}{5}\)
\(\Rightarrow x\times\frac{5}{8}=\frac{2}{5}\)
\(\Rightarrow x=\frac{16}{25}\)
~Std well~
#Thạc_Trân
\(\frac{3}{8}\times x+\frac{1}{4}\times x=\frac{2}{5}\)
\(\left(\frac{3}{8}+\frac{1}{4}\right)\times x=\frac{2}{5}\)
\(\frac{5}{8}\times x=\frac{2}{5}\)
Đến đây tự làm :v
Tính nhanh:
a, ( 21,4 x 35,5 - 25,5 x 21,4 ) x ( 15x12 - 1500 x 0,1 - 30)
b, D=11+11/2+11/6+11/12+11/20+...+11/110
x:0,25+x:0,5+x+x:0,01=21,4
Biểu thức x - 1 - 6 - 4 x x + 7 có nghĩa khi ?
A. x < 1
B. x ≥ 3/2
C. 1 ≤ x ≤ 3 / 2
D. x > 1
4xX-X-X=1,07
`4 xx x -x-x=1,07`
`=> 4 xx x - x xx 1 - x xx 1=1,07`
`=> (4-1-1) xx x=1,07`
`=> 2 xx x =1,07`
`=> x=1,07 : 2`
`=>x=0,535`
`4xx x-x-x=107`
`=>x xx (4-1-1)=1,07`
`=> x xx 2=1,07`
`=>x=1,07:2`
`=>x=0,535`
(1/4xX-1/8)x3/4=1/4
Tim x
(1/4x X -1/8 ) x 3/4 =1/4 1/4 x X -1/8 = 1/4 : 3/4 ( tìm thừa số ) 1/4 x X - 1/8 = 1/3 1/4 x X = 1/3 + 1/8 ( tìm số hạng ) 1/4 x X = 11/24 X = 11/24 : 1/4 ( tìm thừa số ) X = 11/6
Tìm x
31,6:(x-2,75)=10
\(31,6:\left[x-2,75\right]=10\)
\(\Rightarrow\left[x-2,75\right]=31,6:10\)
\(\Rightarrow\left[x-2,75\right]=3,16\)
\(\Rightarrow x=3,16+2,75=5,91\)
31,6 : ( x - 2,75 ) = 10
x - 2,75 = 31,6 : 10
x - 2,75 = 3,16
x = 3,16 + 2,75
x = 5,91
x-2,75=31,6:10
x-2,75=3,16
x=3,16+2,75
x=6,91