a) \(\sqrt{2x^2-\sqrt{2}x+\frac{1}{4}}=\sqrt{2}x\)

⇔ \(2x^2-\sqrt{2}x+\frac{1}{4}=2x^2\)

⇔ \(-\sqrt{2}x+\frac{1}{4}=0\)

⇔ \(\sqrt{2}x=\frac{1}{4}\)

⇔ \(x=\frac{\sqrt{2}}{8}\)

b) \(\sqrt{4x+8}+\frac{1}{3}\sqrt{9x+18}=3\sqrt{\frac{x+2}{4}}+\sqrt{2}\)

⇔ \(2\sqrt{x+2}+\frac{1}{3}\cdot3\sqrt{x+2}=\frac{3\sqrt{x+2}}{2}+\sqrt{2}\)

⇔ \(3\sqrt{x+2}-\frac{3\sqrt{x+2}}{2}=\sqrt{2}\)

⇔ \(\frac{3\sqrt{x+2}}{2}=\sqrt{2}\)

⇔ \(\frac{3}{2}=\frac{\sqrt{2}}{\sqrt{x-2}}\)

⇔ \(\sqrt{\frac{9}{4}}=\sqrt{\frac{2}{x+2}}\)

⇔ \(\frac{2}{x+2}=\frac{9}{4}\)

⇔ \(x+2=\frac{8}{9}\)

⇔ \(x=\frac{8}{9}-2=-\frac{10}{9}\)

thế à!

\(24,7dm=2,47m\)

\(123,08cm=1,2308m\)

\(2,34kg=0,0234ta\)

\(705kg=0,705tan\)

Where are the even numbers? 

Gọi số cần tìm là a :

a - 1 chia hết cho 3 ; 5 nhưng chia 4 dư :

 3 - 1 = 2

a - 1 = { 15 ; 30 ; 45 ; 60 ; ....}

Nhưng vì a - 1 chia 4 dư 2 nên a - 1 = 30

a = 30 + 1

a = 31

93942 : 12 = 7528.5

     A = 1125 : 3² + 4³ . 125 - 125 : 5²

 A = 1125 : 9 + 64 . 125 - 125 . 25

A = 125 + 64 .125 - 125 . 25

A = 125 . ( 1 + 64 - 25 )

A = 125 . 40

A = 5000

AB DÀI 30 KM BN NHÉ

THANK

CHÚC BN HỌC GIỎI