X + X x 2 + X x 4 = 84

X x (1 + 2 + 4) = 84

X x 7 = 84

X = 84 : 7

X = 12

x+x:0,5+x:0,25= 84

=> x: ( 1+0,5+0,25)= 84

=> x: 1,75= 84

=> x=147

ok

bai nay co rui ma bn

Tìm x à?

x+x=0,125+x:(0,5+0,25+0,75)=1/2

x+x=0,125+          x:1,5        =1/2

x+x=                     x:1,5         =1/2-0,125

x+x=                     x:1,5           =0,375

x+x=                     x                 =0,375x1,5

x+x=                     x            =     0,5625

x+x=0,5625x2

x+x=1,125

=x*1+x:0,125+x:0,5+x:0,25-x:0,75=1/2

=x*[1+0,125+0,5+0,25-0,75]=1/2

=x*0,125=1/2

=x         =1/2*0,125

 x=0.0625

ính bằng cách thuận tiện nhất:

0.5 x 17 x 5 + 0.25 x 520 + 31 x 2.5

=>2,5x17+2.5x52+2,5x31

=2,5(17+52+31)

=2,5x100

=250

\(0,5\times17\times5\times0,25\times520+31\times2,5\)

\(\Rightarrow2,5\times17+2,5\times52+2,5\times31\)

\(\Rightarrow2,5\times\left(17+52+31\right)\)

\(\Rightarrow2,5\times100\)

\(\Rightarrow2500\)

\(\frac{85}{2}\)+ 130+ \(\frac{155}{2}\)

\(\frac{85}{2}\)+\(\frac{260}{2}\)+\(\frac{155}{2}\)

250

20.18 x 89 + 20.18 x 0.2 + 20.18 x 0.5 + 20.18 x 0.25

= 20.18 ( 89 + 0.2 + 0.5 + 0.25 )

= 360 . 89,95

= 32382

Ủng hộ ae ơiii

20.18 x 89 + 20.18 x 0.2 + 20.18 x 0.5 + 20.18 x 0.25

= 20.18 x ( 89 + 0.2 + 0.5 + 0.25)

= 2018 x 89.95

= 1815.191

20.18×89+20.18×0.2+20.18×0.5+20.18×0.25

=20.18×(89+0.2+0.5+0.25)

=20.18×89.95

=1851.191

HỌCTỐT

   x + x/0,25 + x/0,5 + x/0,125 = 0,45

<=> x + x( 1/0,25 + 1/0,5 + 1/0,125 ) = 0,45

<=> x + x( 4 + 2 + 8 ) = 0,45

<=> x + 14x = 0,45

<=> 15x = 0,45

<=>    x   = 0,45 : 15

<=>    x   = 0,03

    ~~~~~Hok tốt~~~~~

Thnk nha

b) Ta có: \(3+\left(x-5\right)=2\left(3x-2\right)\)

\(\Leftrightarrow3+x-5=6x-4\)

\(\Leftrightarrow x-2-6x+4=0\)

\(\Leftrightarrow-5x+2=0\)

\(\Leftrightarrow-5x=-2\)

\(\Leftrightarrow x=\dfrac{2}{5}\)

Vậy: \(S=\left\{\dfrac{2}{5}\right\}\)

c) Ta có: \(2\left(x-0.5\right)+3=0.25\left(4x-1\right)\)

\(\Leftrightarrow2x-1+3=x-\dfrac{1}{4}\)

\(\Leftrightarrow2x+2-x+\dfrac{1}{4}=0\)

\(\Leftrightarrow x+\dfrac{9}{4}=0\)

\(\Leftrightarrow x=-\dfrac{9}{4}\)

Vậy: \(S=\left\{-\dfrac{9}{4}\right\}\)

d) Ta có: \(2\left(x-\dfrac{1}{4}\right)-4=-6\left(-\dfrac{1}{3}x+0.5\right)+2\)

\(\Leftrightarrow2x-\dfrac{1}{2}-4=2x-3+2\)

\(\Leftrightarrow2x-\dfrac{9}{2}=2x-1\)

\(\Leftrightarrow2x-2x=-1+\dfrac{9}{2}\)

\(\Leftrightarrow0x=\dfrac{7}{2}\)(vô lý)

Vậy: \(S=\varnothing\)

b. 

→ -2 + x = 6x - 4

→ -2 + 4 = 6x - x

→ 2 = 5x

→ x = \(\dfrac{2}{5}\) 

Vậy, phương trình có tập nghiệm S = {\(\dfrac{2}{5}\)}