K hiểu 😐😐😐

\(1,\\ a,=x^3-5x\\ b,=3x^3y-6x^3y^2+9xy\\ c,=6x^2-6x-36\\ d,=x^3+2x^2y-3xy^2\\ 2,\\ a,=4x^2-25\\ b,=x^2-6x+9\\ c,=9x^2+24x+16\\ d,=x^3-6x^2y+12xy^2-8y^3\\ e,=125x^3+225x^2y+135xy^2+27y^3\\ f,=125-x^3\)

\(g,=8y^3+x^3\\ 3,\\ a,=x\left(x+2\right)\\ b,=\left(x-3\right)^2\\ c,=\left(x-y\right)\left(y+5\right)\\ d,=2x\left(y+1\right)-y\left(y+1\right)=\left(2x-y\right)\left(y+1\right)\\ e,=6x^2y^2\left(xy^2+2y-3x\right)\)

5) a) 2x(x^2 - 9) = 0

<=> 2x(x - 3)(x + 3) = 0

<=> x = 0 hoặc x = 3 hoặc x = -3

b) 2x(x - 2021) - x + 2021 = 0

<=> (2x - 1)(x - 2021) = 0

<=> 2x - 1 = 0 hoặc x - 2021 = 0

<=> x = 1/2 hoặc x = 2021

c) 4x^2 - 16x = 0

<=> 4x(x - 4) = 0

<=> x = 0 hoặc x = 4

d) (3x + 7)^2 - (x + 1)^2 = 0

<=> (3x + 7 + x + 1)(3x + 7 - x - 1) = 0

<=> (4x + 8)(2x + 6) = 0

<=> 4x + 8 = 0 hoặc 2x + 6 = 0

<=> x = -2 hoặc x = -3

mình giải tạm nha

a: Ta có: \(A=-x^2+2x+5\)

\(=-\left(x^2-2x-5\right)\)

\(=-\left(x^2-2x+1-6\right)\)

\(=-\left(x-1\right)^2+6\le6\forall x\)

Dấu '=' xảy ra khi x=1

b: Ta có: \(B=-x^2-8x+10\)

\(=-\left(x^2+8x-10\right)\)

\(=-\left(x^2+8x+16-26\right)\)

\(=-\left(x+4\right)^2+26\le26\forall x\)

Dấu '=' xảy ra khi x=-4

c: Ta có: \(C=-3x^2+12x+8\)

\(=-3\left(x^2-4x-\dfrac{8}{3}\right)\)

\(=-3\left(x^2-4x+4-\dfrac{20}{3}\right)\)

\(=-3\left(x-2\right)^2+20\le20\forall x\)

Dấu '=' xảy ra khi x=2

d: Ta có: \(D=-5x^2+9x-3\)

\(=-5\left(x^2-\dfrac{9}{5}x+\dfrac{3}{5}\right)\)

\(=-5\left(x^2-2\cdot x\cdot\dfrac{9}{10}+\dfrac{81}{100}-\dfrac{21}{100}\right)\)

\(=-5\left(x-\dfrac{9}{10}\right)^2+\dfrac{21}{20}\le\dfrac{21}{20}\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{9}{10}\)

e: Ta có: \(E=\left(4-x\right)\left(x+6\right)\)

\(=4x+24-x^2-6x\)

\(=-x^2-2x+24\)

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

\(=-\left(x^2+2x+1-25\right)\)

\(=-\left(x+1\right)^2+25\le25\forall x\)

Dấu '=' xảy ra khi x=-1

f: Ta có: \(F=\left(2x+5\right)\left(4-3x\right)\)

\(=8x-6x^2+20-15x\)

\(=-6x^2-7x+20\)

\(=-6\left(x^2+\dfrac{7}{6}x-\dfrac{10}{3}\right)\)

\(=-6\left(x^2+2\cdot x\cdot\dfrac{7}{12}+\dfrac{49}{144}-\dfrac{529}{144}\right)\)

\(=-6\left(x+\dfrac{7}{12}\right)^2+\dfrac{529}{24}\le\dfrac{529}{24}\forall x\)

Dấu '=' xảy ra khi \(x=-\dfrac{7}{12}\)

1,\(=4x\left(x-\dfrac{3}{2}\right)\)
2,\(=-7y^3\left[2x^2y\left(2y+x\right)+3\right]\)
3, = 4x(a-b)-6xy(a-b)
=2x(a-b)(2-3y)
4,
=3(2x+1)-(2x-5)(2x+1)
=(3-2x+5)(2x+1)
=(8-2x)(2x+1)
=2(4-x)(2x+1)
 

5: \(4\left(x-3\right)^2+2x\left(3-x\right)\)

\(=\left(x-3\right)\left(4x-12\right)-2x\left(x-3\right)\)

\(=\left(x-3\right)\left(2x-12\right)\)

\(=2\left(x-6\right)\left(x-3\right)\)

8: \(\left(3x-1\right)^2-\left(x+3\right)^2\)

\(=\left(3x-1-x-3\right)\left(3x-1+x+3\right)\)

\(=\left(2x-4\right)\left(4x+2\right)\)

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

\(A=\left(x+2y\right)^2-2\left(x+y\right)\left(x+2y\right)+\left(x+y\right)^2\\ A=\left(x+2y-x-y\right)^2=y^2\\ A=1000^2=1000000\)

???????????????????????

a) 2+3𝑥=−15−19

3x= -15 - 19 -2

3x = -36

x= -12

b) 2𝑥−5=−17+12

2x = -17 + 12 + 5

2x = 0

x = 0

c) 10−𝑥−5=−5−7−11

-x = -5 - 7 - 11 - 10 + 5

-x = -28

x = 28

d) |𝑥|−3=0

|x|= 3

x = \(\pm\)3

e) (7−|𝑥|).(2𝑥−4)=0

th1 : ( 7 - | x| ) = 0

|x|= 7

x=\(\pm\)7

th2: ( 2x-4) = 0

2x = 4

x= 2

f) −10−(𝑥−5)+(3−𝑥)=−8

-10 - x + 5 + 3 - x = -8

-10 + 5 + 3 + 8 = 2x

2x= 6

x = 3

g) 10+3(𝑥−1)=10+6𝑥

10 + 3x - 3 = 10 + 6x

3x - 6x = 10 - 10 + 3

-3x = 3

x= -1

h) (𝑥+1)(𝑥−2)=0

th1: x+1= 0

x = -1

x-2=0

x=2

hok tốt!!!

a) Ta có: 

a) Ta có: 

máy mình nó bị lỗi nên bn thông cảm nhé trả lời vừa đây mới là đugs