a: \(\frac{4^5\cdot10\cdot5^6+25^5\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(=\frac{2^{10}\cdot2\cdot5\cdot5^6+5^{10}\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}=\frac{2^8\cdot5^7\left(2^3+3^3\right)}{2^5\cdot5^4\left(2^3+3^3\right)}\)

\(=2^3\cdot5^3=10^3=1000\)

b: \(149-\left(35:x+3\right)\cdot17=13\)

=>\(\left(35:x+3\right)\cdot17=149-13=136\)

=>35:x+3=136:17=8

=>35:x=8-3=5

=>\(x=\frac{35}{5}=7\)

c: \(121:11-\left(4x+5:3\right)=4\)

=>11-(4x+5/3)=4

=>4x+5/3=11-4=7

=>\(4x=7-\frac53=\frac{21}{3}-\frac53=\frac{16}{3}\)

=>\(x=\frac{16}{3}:4=\frac43\)

d: \(720:\left\lbrack41-\left(2x-5\right)\right\rbrack=40\)

=>\(41-\left(2x-5\right)=\frac{720}{40}=18\)

=>2x-5=41-18=23

=>2x=28

=>\(x=\frac{28}{2}=14\)

e: Sửa đề: (x+1)+(x+2)+(x+3)+...+(x+100)=5700

=>100x+(1+2+3+...+100)=5700

=>\(100x+100\cdot\frac{101}{2}=5700\)

=>x+50,5=57

=>x=57-50,5

=>x=6,5

máy tính ra :

1.5383844_x10¹¹

=153838440000

    \(x+15,7=7,2\times2,5\)
    \(x+15,7=18\) 
    \(x=18-15,7\)   
    \(x=2,3\)
    Vậy \(x=2,3\)


    \(x\times9,1+x\times1,9=26,4\)
⇔\(x\times\left(9,1+1,9\right)=26,4\)
    \(x\times10=26,4\)
    \(x=26,4:10\)
    \(x=2,64\)
    Vậy \(x=2,64\)


    \(x:12,5=48-45,66\)
    \(x:12,5=2,34\)
    \(x=2,34\times12,5\)
    \(x=29,25\)
    Vậy \(x=29,25\)


    Sửa đề:
    \(x\times9,9+x\times10=12,5\)
⇔\(x\times\left(9,9+10\right)=12,5\)
    \(x\times19,9=12,5\)
    \(x=12,5:19,9\)
    \(x=\dfrac{125}{199}\)
    Vậy \(x=\dfrac{125}{199}\)
\(#PeaGea\)

xxxx

a: \(\overline{xx}+\overline{x}+5=125\)

=>10x+x+x=120

=>12x=120

=>x=10

b: \(\overline{xxx}+\overline{xx}+x+x=992\)

=>100x+10x+x+10x+x+2x=992

=>124x=992

=>x=8(nhận)

c: \(4725+\overline{xxx}+\overline{xx}+\overline{x}=54909\)

=>100x+10x+x+10x+x+x=54909-4725

=>123x=50184

=>x=408

d: \(\overline{xxx}-\overline{xx}-\overline{x}-25=4430\)

=>100x+10x+x-10x-x-x=4430+25

=>99x=4425

=>x=4425/99(loại)

e: \(\overline{xxx}+\overline{xx}+\overline{x}+\overline{x}+\overline{x}+1=1001\)

=>111x+11x+3x=1000

=>125x=1000

=>x=8

f: \(35655-\overline{xxx}-\overline{xx}-\overline{x}=5274\)

=>35655-111x-11x-x=5274

=>35655-123x=5274

=>123x=35655-5274=30381

=>x=247

[ 61 + ( 53 - x ) ] x 17 = 1785

61 + 53 - x = 1785 : 17

114 - x = 105

x = 114 - 105

x = 9

\(\left[61+\left(53-x\right)\right].17=1785\)

\(\Leftrightarrow61+\left(53-x\right)=105\)

\(\Leftrightarrow53-x=44\Leftrightarrow x=9\)