mn giúp em vs ạ em cần gấp cảm ơn ạ 

Tham khảo nhé :

- Once upon a time, hence he has two brothers, who he is extremely greedy, the gentle brother hard. After his parents died he married people in particular have all the wealth plundered and people just leave me a star fruit tree in the corner of the garden.
The younger brother has not been a division of property complaints, building tree huts near indenture. Every day, people you fertilize trees and hired contract to earn money for themselves.
Star fruit trees to have grown, he suddenly wrong laden years. So glad brother.
One day, suddenly there where strange bird flying to the tree and eat indenture contract of em. Seeing this brother with bird sad lament. Strange bird replied, "Eat a piece of gold returns three gang carried away bags that contained".
A few days later as promised birds came out to meet him or her to an island a lot of gold, silver and jewels. Brother watched from above the island and took gold filled pocket only three rides on the back iron and returning birds.
The younger brother used to go home to get some gold in exchange for grain to help the needy in the village.
Seeing this, the play and asked him to change the house, his farm to take his brother's contract tree. Brother again not complain and agree to change for him.
That year also wrong tree laden contract strange bird to eat well. Who he also lamented tearfully. Chim responded and promised to go for gold bearing.
The nature of greed, people somehow connected to his wife of six bags of pig iron and contains lots of gold.
A few days later he met him strange bird and brought him to the island full of gold and jewels. Brother took gold on the island packed into their bags carried away six iron.
On the way back, having to carry a lot of gold and silver to fly against the wind, fatigue strange bird wings. Birds urged him to throw off his gold but people refused to listen.
Phoenix exasperating, unbearable heaviness brother knocked it tilted wing greed and gold into the sea. That was the end greedy.

The legend tells of star fruit tree from house two brothers orphaned early. Brother lazy nature, scrambled out of the reform houses, chasing children live in huts.
How much hard work for the couple poured all brothers. In contrast, the brother kind of hard, stay up late doing pit early training. Seeing children grow tasty tree contract, with a phoenix to change his contract for gold, the gold accounting bouncing my greed. Finally sow sow personally met, who he held in his hand the bag of gold into the sea and died

a: =>x(x-3)(x+3)=0

=>\(x\in\left\{0;3;-3\right\}\)

b:=>(x-2)(x-2-x-5)=0

=>x-2=0

=>x=2

c:=>(x-3)^2=0

=>x-3=0

=>x=3

d: =>(x-1)(x-6)=0

=>x=1 hoặc x=6

a)

\(=\left(\dfrac{x}{x+3}-\dfrac{x^2+9}{\left(x-3\right)\left(x+3\right)}\right):\left(\dfrac{3x+1}{x\left(x-3\right)}-\dfrac{1}{x}\right)\)

\(=\left(\dfrac{x\left(x-3\right)}{\left(x+3\right)\left(x-3\right)}-\dfrac{x^2+9}{\left(x-3\right)\left(x+3\right)}\right):\left(\dfrac{3x+1}{x\left(x-3\right)}-\dfrac{x-3}{x\left(x-3\right)}\right)\)

\(=\left(\dfrac{x^2-3x-x^2-9}{\left(x+3\right)\left(x-3\right)}\right):\left(\dfrac{3x+1-x+3}{x\left(x-3\right)}\right)\)

\(=\dfrac{-3\left(x+3\right)}{\left(x+3\right)\left(x-3\right)}:\dfrac{2x+4}{x\left(x-3\right)}\)

\(=\dfrac{-3}{\left(x-3\right)}\cdot\dfrac{x\left(x-3\right)}{2x+4}\\ =\dfrac{-3x}{2x+4}\)

b)

với `x=-1/2` (tmđk) ta có

\(\dfrac{-3\cdot\left(\dfrac{-1}{2}\right)}{2\cdot\left(-\dfrac{1}{2}\right)+4}=\dfrac{1}{2}\)

c)

để P=x thì

\(\dfrac{-3x}{2x+4}=x\)

\(=>-3x=\left(2x+4\right)\cdot x\)

\(-3x=2x^2+4x\)

\(2x^2+4x+3x=0\)

\(2x^2+7x=0\)

\(x\left(2x+7\right)=0\)

\(=>\left[{}\begin{matrix}x=0\\2x+7=0\end{matrix}\right.=>\left[{}\begin{matrix}x=0\left(loại\right)\\x=-\dfrac{7}{2}\left(tm\right)\end{matrix}\right.\)

d)

mik ko bt lm=)

Bài 2:

a) Để hàm số đồng biến thì m+1>0

hay m>-1

b) Để hàm số đi qua điểm A(2;4) thì

Thay x=2 và y=4 vào hàm số, ta được:

\(\left(m+1\right)\cdot2=4\)

\(\Leftrightarrow m+1=2\)

hay m=1

c) Để hàm số đi qua điểm B(2;-4) thì

Thay x=2 và y=-4 vào hàm số, ta được:

\(2\left(m+1\right)=-4\)

\(\Leftrightarrow m+1=-2\)

hay m=-3

Bài 1:

b) Ta có: \(5\cdot\sqrt{25a^2}-25a\)

\(=5\cdot5\cdot\left|a\right|-25a\)

\(=-25a-25a=-50a\)

a: AC=căn 20^2-12^2=16cm

AH=12*16/20=9,6cm

b: ΔABC vuông tại A có AH là đường cao

nên AH^2=HB*HC(hệ thức lượng)

c: ΔABK vuông tại B có BH là đường cao

nên AH*AK=AB^2

ΔABC vuông tại A có AH là đường cao

nên BH*BC=AB^2

=>BH*BC=AH*AK