diễn giải ra nhé

X x \(\dfrac{3}{4}\)+ X x\(\dfrac{1}{5}\)+ X x \(\dfrac{1}{20}\)+ X= 1000

Bài 2

a) x=5

b)x=1

a) \(x+215=480\)

\(x=480-215\)

\(x=265\)

b) \(725-x=185:5\)

\(725-x=37\)

\(x=725-37\)

\(x=688\)

c) \(x\times\dfrac{1}{3}+x\times\dfrac{4}{3}=\dfrac{2}{3}\)

\(x\times\left(\dfrac{1}{3}+\dfrac{4}{3}\right)=\dfrac{2}{3}\)

\(x\times\dfrac{5}{3}=\dfrac{2}{3}\)

\(x=\dfrac{2}{3}:\dfrac{5}{3}=\dfrac{2}{3}\times\dfrac{3}{5}\)

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

d) \(\left(\dfrac{13}{5}+\dfrac{2}{3}\right):x=5\)

\(\dfrac{49}{15}:x=5\)

\(x=\dfrac{49}{15}:5=\dfrac{49}{15}\times\dfrac{1}{5}\)

\(x=\dfrac{49}{75}\)

a)x + 215 = 480 

x = 480 - 215 

x = 265 

b) 725 - x = 185 : 5 

    725 - x = 37

              x = 725 - 37 

             x = 688

c, \(x\) \(\times\) \(\dfrac{1}{3}\) + \(x\) \(\times\) \(\dfrac{4}{3}\) = \(\dfrac{2}{3}\)

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

    \(x\) \(\times\) \(\dfrac{5}{3}\)          = \(\dfrac{2}{3}\)

    \(x\)                  = \(\dfrac{2}{3}\) : \(\dfrac{5}{3}\)

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

d, (\(\dfrac{13}{5}\) + \(\dfrac{2}{3}\)) : \(x\) = 5

     \(\dfrac{49}{15}\) : \(x\)        = 5

             \(x\)           = \(\dfrac{49}{15}\) : 5

              \(x\)         = \(\dfrac{49}{75}\)

1)1/9 x 3^x = 2187:81=27

            3^x=27:1/9=243=3⁵

            =>x=5

\(\frac{1}{9}.3^4.3^x=3^7\)

\(\Leftrightarrow3^x=3^7:\frac{1}{9}:3^4=243\)

\(\Leftrightarrow3^x=3^5\)

\(\Leftrightarrow x=5\)

1.53x201=10653

2.

a)4 xX-15x4=6x15+X

<=>4x-60=90+x

<=>4x-x=60+90

<=>3x=150

<=>x=50

b(102+28-2x):20-5=1

<=>(130-2x):20=6

<=>130-2x=120

<=>2x=10

<=>x=5

c)1999x-x=1999+1997+1999

<=>1998x=5995

<=>\(x\approx3\)

d)105-5x=150:15

<=>105-5x=10

<=>5x=95

<=>x=19

e)(x+1)+(x+2)+(x+3)+...+(x+6)=78

<=>6x+21=78

<=>6x=57

<=>x=9,5

1) 53x201=53x200+53=10600+53=10653

2a)

4x-15x4=6x15+x

4x-60=90+x

4x-x=90+60

3x=150

x=50

b) x=5

c) x=3

d)x=19

e) x=9,5

các bạn ơi 4x và 3x là j vậy ??

\(\frac{10}{3}.x+\frac{67}{4}=\frac{53}{4}\)

\(\frac{10}{3}.x=\frac{53}{4}-\frac{67}{4}\)

\(\frac{10}{3}.x=-\frac{7}{2}\)

\(x=-\frac{7}{2}:\frac{10}{3}\)

\(x=-\frac{21}{20}\)

a) \(215+x=400\)

\(\Rightarrow x=400-215\)

\(\Rightarrow x=185\)

b) \(12,5-2x=\dfrac{1}{5}\)

\(\Rightarrow2x=12,5-\dfrac{1}{5}\)

\(\Rightarrow2x=\dfrac{123}{10}\)

\(\Rightarrow x=\dfrac{123}{10}:2\)

\(\Rightarrow x=\dfrac{123}{20}\)

còn câu c d nhanh cậu ơi

Bạn xem lại đề phần e nha .

\(c)x.0,25-\dfrac{3}{25}:x=2\dfrac{1}{4}\)

\(x.0,25-\dfrac{25}{3}.x=\dfrac{9}{4}\)

\(x.\left(0,25-\dfrac{25}{3}\right)=\dfrac{9}{4}\)

\(x.\dfrac{-97}{12}=\dfrac{9}{4}\)

\(x=\dfrac{-27}{97}\)

\(d)\left(x-\dfrac{1}{3}\right).\left(x-\dfrac{1}{4}\right)=0\)

Do : 2 số đó nhân với nhau bằng 0 nên một trong 2 số là số 0.

Do đó :

\(Th1:x-\dfrac{1}{3}=0\)

\(x=\dfrac{1}{3}\)

\(Th2:x-\dfrac{1}{4}=0\)

\(x=\dfrac{1}{4}\)

\(\frac{7}{4}-x.\frac{3}{4}=\frac{5}{19}\)

\(\Rightarrow1+\frac{3}{4}-x.\frac{3}{4}=\frac{5}{9}\)

\(\Rightarrow\frac{3}{4}.\left(1-x\right)=\frac{5}{9}-1=-\frac{4}{9}\)

\(\Rightarrow1-x=-\frac{4}{9}:\frac{3}{4}=-\frac{16}{27}\)

\(\Rightarrow x=1-\left(-\frac{16}{27}\right)=1+\frac{16}{27}=1\frac{16}{27}\)

thank you

không có j nha bạn

10/3 x 1/2 - ( 1/2 x X - 1/3) + 1/5 = 3/5 :1/2

5/3 - ( 1/2 x X - 1/3) + 1/5 = 6/5

5/3 - ( 1/2 x X - 1/3) = 6/5 + 1/5

5/3 - ( 1/2 x X - 1/3) = 7/5

1/2 x X - 1/3 = 5/3 - 7/5

1/2 x X - 1/3 = 4/15

1/2 x X = 4/15 + 1/3

1/2 x X = 9/15

X = 9/15 : 1/2

X = 18/15.

Đây nha

bạn duy chưa rút gọn nha