(32+21)2

= 53 . 2

= 106

-HT-

( 32 + 21 )2

=53 . 2

=106

chúc  ban hok tốt !!

a. ta có :

\(E=\frac{3+2-x}{x-2}=\frac{3}{x-2}-1\text{ là số nguyên khi }x-2\text{ là ước của 3}\)

hay \(x-2\in\left\{\pm1,\pm3\right\}\Leftrightarrow x\in\left\{-1,1,3,5\right\}\)

b. ta có 

\(F=\frac{4x-2+5}{1-2x}=-2+\frac{5}{1-2x}\text{ là số nguyên khi }1-2x\text{ là ước của }5\)

hay \(1-2x\in\left\{\pm1,\pm5\right\}\Leftrightarrow x\in\left\{3,1,0,-2\right\}\)

Đặt \(a=2k;b=-3k;c=-4,5k\)

Thay vào P ta được

 \(P=\frac{3.2k-2.\left(-3k\right)}{8.2k+3k+3\left(-4,5k\right)}=\frac{6k+6k}{16k+3k-13,5k}=\frac{12k}{5,5k}=\frac{12}{5.5}=12.\frac{2}{11}=\frac{24}{11}\)

\(\left(x^2-8x\right)-3x+24=0\)

\(\Leftrightarrow x\left(x-8\right)-3\left(x-8\right)=0\)

\(\Leftrightarrow\left(x-3\right)\left(x-8\right)=0\Leftrightarrow x=3;x=8\)

bài 59; tìm x biết

2, ( x mũ 2 - 8x ) - 3x + 24 = 0

x= 3 ; x =  8 

Tui tưởng cuối trang có đáp án?

huh ???

ta có :

\(\frac{2}{y-2}=\frac{3}{z+2}\Leftrightarrow\frac{2}{y}=\frac{3}{z+5}\Leftrightarrow\frac{4}{y^2}=\frac{9}{\left(z+5\right)^2}\) hay ta có :\(\left(z+5\right)^2=\frac{9}{4}y^2\Rightarrow2y^2-\frac{9}{4}y^2=-25\Leftrightarrow y^2=100\)

TH1.\(y=10\Rightarrow\frac{4}{x+1}=\frac{2}{10-2}=\frac{3}{z+2}\Leftrightarrow\hept{\begin{cases}x=15\\z=10\end{cases}}\)

TH2.\(y=-10\Rightarrow\frac{4}{x+1}=\frac{2}{-10-2}=\frac{3}{z+2}\Leftrightarrow\hept{\begin{cases}x=-25\\z=-20\end{cases}}\)

1.I do => I did

2.do => did

3.goes => is going

4.are => \

1. Tìm lỗi :

1, What did you do last night ?I do my home work => did

2, What home do you get up yesterday morning ? => time

3, Where is your mother now ?She goes shopping => is going

4, Which class you are in  ? I'm in class 6B => are you

(10x + 2⁴) . 7⁴ = 2.7⁷

=> 10x + 16 = 2.7⁷ : 7⁴

=> 10x + 16 = 686

=> 10x = 686 - 16

=> 10x = 670

=> x = 67

cảm ơn Nhạt