trả lời 

1tấn =1000kg

1 tấn=1000kg

\(x:\frac{4}{5}=\frac{5}{2}\)

\(x=\frac{5}{2}×\frac{4}{5}\)

\(x=2\)

vậy x=2

\(45,5:x=1,25\)

x=45,5:1,25

x=36,4

vậy x=36,4

\(x:\frac{4}{5}=\frac{5}{2}\)

\(x=\frac{5}{2}\times\frac{4}{5}\)

\(x=2\)

\(45,5:x=1,25\)

\(x=45,5:1,25\)

\(x=36,4\)

Học tốt

Answer:

I get up at half past six

I get up at half past six

mong các bạn giúp mik ạ. mik cảm ơn!

Trả lời :

Hi. What (1)............. do you get up?

=> Hi. What time do you get up?

Dịch : Chào. Bạn dậy vào lúc mấy giờ?

Ta có : 3^{2x + 1} = 27

=> 3^{2x + 1} = 3³

=> 2x + 1 = 3

=> 2x = 2

=> x = 1

Vậy x = 1

\(3^{2x+1}=27\)

\(\Rightarrow3^{2x+1}=3^3\)

\(\Rightarrow2x+1=3\)

\(\Rightarrow2x=3-1\)

\(\Rightarrow2x=2\)

\(\Rightarrow x=1\)

Vậy x = 1

Bài 2 :

\(a,B=-\sqrt{\left(-4\right)^2+\left(-3\right)^2}\)

\(B=-\sqrt{16+9}\)

\(B=-\sqrt{25}\)

\(B=-5\)

b, Bạn viết rõ ra nhé

Học tốt

\(\left[\left(-\frac{1}{2}\right)^2\right]^5va\left(-\frac{1}{2}\right)^{10}\)

\(\left(-\frac{1}{2}\right)^{2×5}va\left(-\frac{1}{2}\right)^{10}\)

\(\left(-\frac{1}{2}\right)^{10}=\left(-\frac{1}{2}\right)^{10}\)

\(b=-\sqrt{\left(-4\right)^2+\left(-3\right)^2}\)

\(b=-\sqrt{16+9}\)

\(b=-\sqrt{25}\)

\(b=-5\)

\(12-5.\left(x-2\right)=4.\left(6-x\right)\)

\(12-5x+10=24-4x\)

\(-5x+4x=24-12-10\)

\(-x=2\)

\(\Rightarrow x=-2\)

Học tốt

12 - 5( x - 2 ) = 4( 6 - x )

<=> 12 - 5x + 10 = 24 - 4x

<=> -5x + 4x = 24 - 12 - 10

<=> -x = 2

<=> x = -2

\(\frac{x}{-1}=-\frac{1}{3}-\frac{5}{9}\)

\(\frac{x}{-1}=-\frac{8}{9}\)

x.-8=9.-1

x.-8=-9

x=-9:-8

x=\(\frac{9}{8}\)

vậy \(x=\frac{9}{8}\)

Bài làm

\(\frac{5}{9}+\frac{x}{-1}=-\frac{1}{3}\Leftrightarrow\frac{5}{9}-\frac{9x}{9}=\frac{-3}{9}\)

\(\Leftrightarrow8-9x=0\Leftrightarrow x=\frac{8}{9}\)

=\(\left(-\frac{1}{2}+\frac{4}{3}\right).\frac{16}{5}-\frac{6}{5}\)

\(=\frac{5}{6}.\frac{16}{5}-\frac{6}{5}\)

\(=\frac{8}{3}-\frac{6}{5}\)

\(=\frac{22}{15}\)

\(=\frac{20}{3}-\frac{16}{3}.\left(\frac{3}{4}\right)^2\)

\(=\frac{20}{3}-\frac{16}{3}.\frac{9}{16}\)

\(=\frac{20}{3}-3\)

\(=\frac{11}{3}\)

Ta có : \(\frac{2x+5}{x+1}=\frac{2x+2+3}{x+1}=\frac{2\left(x+1\right)+3}{x+1}=2+\frac{3}{x+1}\)

Vì 2 \(\inℤ\Rightarrow\frac{3}{x+1}\inℤ\Rightarrow3⋮x+1\Rightarrow x+1\inƯ\left(3\right)\Rightarrow x+1\in\left\{1;3;-1;-3\right\}\)

=> \(x\in\left\{0;2-2;-4\right\}\)

Để \(\frac{3x-1}{2x-1}\inℤ\Rightarrow3x-1⋮2x-1\Rightarrow2\left(3x-1\right)⋮2x-1\Rightarrow6x-2⋮2x-1\)

=> \(6x-3+1⋮2x-1\Rightarrow3\left(2x-1\right)+1⋮2x-1\)

Vì \(3\left(2x-1\right)⋮2x-1\)

=> \(1⋮2x-1\Rightarrow2x-1\inƯ\left(1\right)\Rightarrow2x-1\in\left\{1;-1\right\}\Rightarrow x\in\left\{1;0\right\}\)

\(\frac{2x+5}{x+1}=\frac{2\left(x+1\right)+3}{x+1}=2+\frac{3}{x+1}\)

Để phân số nguyên => \(\frac{3}{x+1}\)nguyên

=> \(3⋮x+1\)

=> \(x+1\inƯ\left(3\right)=\left\{\pm1;\pm3\right\}\)

=> \(x=\left\{0;-2;2;-4\right\}\)

\(\frac{3x-1}{2x-1}\)

Để phân số nguyên => \(3x-1⋮2x-1\)

=> \(2\left(3x-1\right)⋮2x-1\)

=> \(6x-2⋮2x-1\)

\(\Rightarrow3\left(2x-1\right)+1⋮2x-1\)

\(\Rightarrow1⋮2x-1\)

\(\Rightarrow2x-1\inƯ\left(1\right)=\left\{\pm1\right\}\)

\(\Rightarrow x=\left\{1;0\right\}\)