http://download.geogebra.org/installers/5.0/?C=M;O=D ?

Bàng, bắp, bí, bìm bìm, bỉ ngạn, bồ công anh, bồ đề ( hoa ), bèo, bơ, bạch đàn, bòng bong, bầu, ..

a) \(\dfrac{3x-1}{x-1}-\dfrac{2x+5}{x+3}=1-\dfrac{4}{\left(x-1\right)\left(x+3\right)}\) ( đk: x ≠ 1 ; x ≠ -3 )

\(\Leftrightarrow\left(3x-1\right)\left(x+3\right)-\left(2x+5\right)\left(x-1\right)=\left(x-1\right)\left(x+3\right)-4\)

\(\Leftrightarrow3x^2+9x-x-3-2x^2+2x-5x+5=x^2+3x-x-3-4\)

\(\Leftrightarrow3x=-9\)

\(\Rightarrow x=-3\left(KTM\right)\)

S = ∅

b) \(\dfrac{13}{\left(x-3\right)\left(2x+7\right)}+\dfrac{1}{2x+7}=\dfrac{6}{\left(x-3\right)\left(x+3\right)}\)

( đk: x ≠ ± 3 ; x ≠ \(\dfrac{-7}{2}\) )

\(\Leftrightarrow13\left(x+3\right)+\left(x-3\right)\left(x+3\right)=6\left(2x+7\right)\)

\(\Leftrightarrow13x+39+x^2-9=12x+42\)

\(\Leftrightarrow x^2-x-12=0\)

\(\Leftrightarrow x^2+3x-4x-12=0\)

\(\Leftrightarrow x\left(x+3\right)-4\left(x+3\right)=0\)

\(\Leftrightarrow\left(x-4\right)\left(x+3\right)=0\)

\(\Rightarrow\left\{{}\begin{matrix}x-4=0\\x-3=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=4\left(TM\right)\\x=3\left(KTM\right)\end{matrix}\right.\)

S = \(\left\{4\right\}\)

\(\dfrac{x^3-\left(x-1\right)^3}{\left(4x+3\right)\left(x-5\right)}=\dfrac{7x-1}{4x+3}-\dfrac{x}{x-5}\) ( đk: x ≠ \(\dfrac{-3}{4}\) ; x ≠ 5 )

\(\Leftrightarrow\) \(x^3-\left(x-1\right)^3=\left(7x-1\right)\left(x-5\right)-x\left(4x+3\right)\)

\(\Leftrightarrow\) \(\left(x-x+1\right)\left(x^2+x^2-x+x^2-2x+1\right)=7x^2-35x-x+5-4x^2-3x\)\(\Leftrightarrow\) \(3x^2-3x+1=3x^2-39x+5\)

\(\Leftrightarrow\) \(36x=4\)

\(\Leftrightarrow\) \(x=\dfrac{1}{9}\)( TM )

\(S=\left\{\dfrac{1}{9}\right\}\)

Theo gt: p + e + n = 46

mà p = e

\(\Rightarrow\) 2p + n = 46 ( 1 )

mà \(n=\dfrac{8}{15}2p\)

\(\Rightarrow n=\dfrac{16}{15}p\) ( 2 )

(1)(2) \(\Rightarrow2p+\dfrac{16}{15}p=46\)

\(\Rightarrow\dfrac{46}{15}p=46\)

\(\Rightarrow p=15\)

\(\Rightarrow n=16\)

( X là nguyên tố P )

Theo gt: p + e + n = 46

mà p = e

\(\Rightarrow\) 2p + n = 46 ( 1 )

mà \(n=\dfrac{8}{15}2p\)

\(\Rightarrow n=\dfrac{16}{15}p\) ( 2 )

(1)(2) \(\Rightarrow2p+\dfrac{16}{15}p=46\)

\(\Rightarrow\dfrac{46}{15}p=46\)

\(\Rightarrow p=15\)

\(\Rightarrow n=16\)

( X là nguyên tố P )

a) \(\dfrac{1}{x+1}-\dfrac{5}{x-2}=\dfrac{15}{\left(x+1\right)\left(2-x\right)}\) ( đk: x ≠ -1; x ≠ 2 )

\(\Leftrightarrow\) \(\dfrac{1}{x+1}+\dfrac{5}{2-x}=\dfrac{15}{\left(x+1\right)\left(2-x\right)}\)

\(\Leftrightarrow\) \(2-x+5\left(x+1\right)=15\)

\(\Leftrightarrow\) \(2-x+5x+5=15\)

\(\Leftrightarrow\)\(4x=8\)

\(\Rightarrow\) \(x=2\) ( KTM )

S = ∅

b) \(1+\dfrac{x}{3-x}=\dfrac{5x}{\left(x+2\right)\left(3-x\right)}+\dfrac{2}{x+2}\) ( đk: x ≠ - 2 ; x ≠ 3 )

\(\Leftrightarrow\) \(\left(x+2\right)\left(3-x\right)+x\left(x+2\right)=5x+2\left(3-x\right)\)

\(\Leftrightarrow\) \(3x-x^2+6-2x+x^2+2x=5x+6-2x\)

\(\Leftrightarrow\) \(3x+6=3x+6\)

\(\Rightarrow\)\(0x=0\) ( TM )

\(\Rightarrow\) Phương trình vô số nghiệm

S = R

c) \(\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{8}{\left(x-1\right)\left(3-x\right)}\) ( đk: x ≠ 1 ; x ≠ 3 )

\(\Leftrightarrow\) \(\dfrac{6}{x-1}+\dfrac{4}{3-x}=\dfrac{8}{\left(x-1\right)\left(3-x\right)}\)

\(\Leftrightarrow\)\(6\left(3-x\right)+4\left(x-1\right)=8\)

\(\Leftrightarrow\) \(18-6x+4x-4=8\)

\(\Leftrightarrow\) \(-2x=-6\)

\(\Rightarrow x=3\) ( KTM )

S = ∅

d) \(\dfrac{x+2}{x-2}-\dfrac{1}{x}=\dfrac{2}{x\left(x-2\right)}\) (đk: x ≠ 2; x ≠ 0 )

\(\Leftrightarrow\) \(x\left(x+2\right)-x+2=2\)

\(\Leftrightarrow\) \(x^2+2x-x+2=2\)

\(\Leftrightarrow\) \(x^2+x=0\)

\(\Leftrightarrow\) \(x\left(x+1\right)=0\)

\(\Rightarrow\left\{{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=0\left(KTM\right)\\x=1\left(TM\right)\end{matrix}\right.\)

S = \(\left\{2\right\}\)

1. What is the national language in Malaysia ?

Ans: In Malaysia, the national language is called the Bahasa Malaysia and it is the language of instruction in schools.

2. When was the national language in Malaysia chosen?

Ans: When Malaysia became independent.

3. Have the Chinese, the Indians and the other non - Malay communities accept the choice of the government ?

Ans: Yes, they have.

4. How has Bahasa Malaysia used in Malaysia?

Ans: It has become the most widely used language in Malaysia.

Bài 1 :
Gọi công thức hợp chất : R₂O_n ; 1 ≤ n ≤ 3

Theo gt: %R + %O = 100%
\(\%R+\dfrac{3}{7}\%R=\dfrac{10}{7}\%R\)

Mà %R + %O = 100

\(\Rightarrow\left\{{}\begin{matrix}\%R=70\%\\\%O=30\%\end{matrix}\right.\)

\(\dfrac{M_R}{70}=\dfrac{M_O}{30}\)

\(\Leftrightarrow\dfrac{2M_R}{70}=\dfrac{16n}{30}\)

\(\Leftrightarrow60M_R=1120n\)

\(\Leftrightarrow M_R=\dfrac{56n}{3}\)

Vậy công thức hợp chất là Fe₂O₃