thay 108 = x - 1 vào M là ra nha

thế ra bao nhiêu ạ

\(\sqrt{108x^3}.\sqrt{3x}=\sqrt{108x^3.3x}=\sqrt{324x^4}=18x^2\)( vì x >= 0)

\(\sqrt{108x^3}.\sqrt{3x}=\sqrt{108x^3.3x}=\sqrt{324x^4}\)

\(=18x^2\) (do \(x\ge0\))

Chúc bạn học tốt!!!

\(\frac{\sqrt{108x^3}}{\sqrt{12x}}=\sqrt{\frac{108x^3}{12x}}=\sqrt{9x^2}=3x\)( vì \(x>0\))

\(\frac{\sqrt{13x^4y^6}}{\sqrt{208x^6y^6}}=\sqrt{\frac{13x^4y^6}{208x^6y^6}}=\sqrt{\frac{1}{16x^2}}=\left|\frac{1}{4x}\right|=\frac{-1}{4x}\)( vì \(x< 0\))

\(x+53,67=139,5\times12\)

\(x+53,67=1674\)

\(x=1620,33\)

\(x-42,3=21,15+13,7\)

\(x-42,3=34,85\)

\(x=77,15\)

\(7,2+x:4=108\)

\(x:4=100,8\)

\(x=403,2\)

\(x\times4-7,2=10,8\)

\(x\times4=18\)

\(x=4,5\)

x + 53,67 = 139,5 x 12

x+53,67=1674

x=1674-53,67

x=1620,33

x - 42,3 = 21,15 + 13,7

x-42,3=34,85

x=34,85+42,3

x=77,15

7,2 + x : 4 = 108

x:4=108-7,2

x:4=100,8

x=100,8x4

x=403,2

x x 4 -7,2 =10,8

x x 4=10,8+7,2

x x 4=18

x=18:4

x=4,5

`x + 53,67 = 139,5 xx 12`

`=>x + 53,67 = 1674`

`=>x=1674-53,67`

`=>x=1620,33`

`-------`

`x - 42,3 = 21,15 + 13,7`

`=>x - 42,3 =34,85`

`=>x=34,85+42,3`

`=>x=77,15`

`-------`

`7,2 + x : 4 = 108`

`=>x:4=108-7,2`

`=>x:4=100,8`

`=>x=100,8 xx 4`

`=>x=403,2`

`-------`

`x xx 4 -7,2 =10,8`

`=>x xx 4=10,8 + 7,2`

`=>x xx 4= 18`

`=>x=18:4`

`=>x=4,5`