\(\left(x:1,5\right)+0,45=7,65\)

=>\(x:1,5=7,65-0,45\)

=>\(x:1,5=7,2\)

=>\(x=7,2\times1,5\)

=>\(x=10,8\)

Vậy x = 10,8

$\left(x:1,5\right)+0,45=7,65$

=>$x:1,5=7,65-0,45$

=>$x:1,5=7,2$

=>$x=7,2\times 1,5$

=>$x=10,8$

Vậy x = 10,8

a) 1,26 : x + 2,34 : x =5

\(1,26\times\frac{1}{x}+2,34\times\frac{1}{x}=5\)

\(\frac{1}{x}\times\left(1,26+2,34\right)=5\)

\(\frac{1}{x}\times3,6=5\)

\(\frac{1}{x}=5:3,6\)

\(\frac{1}{x}=\frac{18}{25}\)

\(x=\frac{25}{18}\)

b) \(x\times3,1+x\times6,9=30,4\)

\(x\times\left(3,1+6,9\right)=30,4\)

\(x\times10=30,4\)

\(x=30,4:10\)

\(x=3,04\)

c) \(x:1,5+0,45=7,65\)

\(x:1,5=7,65-0,45\)

\(x:1,5=7,2\)

\(x=1,5\times7,2\)

\(x=11,1\)

Chúc bn học tốt !

a, Xx3,1+Xx6,9=30,4

   Xx(3,1+6,9)=30,4

   Xx10=30,4

    X=30,4:10

    x=3,04

x=3,04

a, Xx3,1+Xx6,9=30,4

   Xx(3,1+6,9)=30,4

   Xx10=30,4

    X=30,4:10

    x=3,04

b)1,5+2,75+.....+14=85,25

cho minh 100

\(x:100+x.0,99=5,25\)

\(\Leftrightarrow x.\frac{1}{100}+x.\frac{99}{100}=\frac{21}{4}\)

\(\Leftrightarrow x.\left(\frac{1}{100}+\frac{99}{100}\right)=\frac{21}{4}\)

\(\Leftrightarrow x.1=\frac{21}{4}\)

\(\Leftrightarrow x=\frac{21}{4}\)

=5,25 x (18-2-6)
=5,25 x   10
=   52,5
Cái đề bài hay quá bạn ạ

=5,25 x (18-2-6)
=5,25 x   10
=   52,5

\(M_X=\dfrac{1.5}{\dfrac{1.775}{71}}=60\left(g\text{/}mol\right)\)

\(n_X=\dfrac{2.25}{60}=0.0375\left(mol\right)\)

CT : \(C_xH_yO_z\)

\(n_{CaCO_3}=n_{CO_2}=\dfrac{11.25}{100}=0.1125\left(mol\right)\)

\(\Rightarrow n_C=0.1125\left(mol\right)\)

\(m_{bt}=m_{CO_2}+m_{H_2O}=7.65\left(g\right)\)

\(\Rightarrow n_{H_2O}=\dfrac{7.65-0.1125\cdot44}{18}=0.15\left(mol\right)\)

\(\Rightarrow n_H=0.15\cdot2=0.3\left(mol\right)\)

Ta có : 

\(x=\dfrac{n_C}{n_X}=\dfrac{0.1125}{0.0375}=3\)

\(y=\dfrac{n_H}{n_X}=\dfrac{0.3}{0.0375}=8\)

\(M=12\cdot3+8+16z=60\left(g\text{/}mol\right)\)

\(\Rightarrow z=1\)

\(CT:C_3H_8O\)

1) 13,8-4,24-5,76+2,2

=(13,8+2,2)-(4,24+5,76)

=16-10

=6

2)x:1.5+0,45=7,65

x:1,5=7,65-0,45

x:1,5=7,2

x=7,2x1,5

x=10,8

b) x+4,5x2,6=15

x+11,7=15

x=15-11,7

x=3,3

c)(7,4+x)-9,25=5,7

7,4+x=5,7+9,25

7,4+x=14,95

x=14,95-7,4

x=7,55

1, 6

2, a ) 10,8            b) 3,3                 c) 7,55

Ủng hộ nhé !! Chúc bạn học giỏi nếu thắc mắc thì cứ hỏi !

1. 13,8 - 4,24 - 5,76 + 2,2 = (13,8+2.2) - (4,24+5,76)

= 16 - 10

=6