a: =3/5-3/5-5/7=-5/7

b: =-7/4(3/8+5/8)+7/15*-5/14

=-7/4-35/210

=-7/4-1/6

=-21/12-2/12=-23/12

c: =(0,5-1,2):1,05-(-125/8)-1/12

=25/63+125/8-1/12

=8033/504

\(g,\left(x^2y-xy+xy^2+y^3\right).3xy^2\\ =\left(3xy^2.x^2y\right)-\left(3xy^2.xy\right)+\left(3xy^2.xy^2\right)+\left(3xy^2.y^3\right)\\ =3x^3y^3-3x^2y^3+3x^2y^4+3xy^5\)

\(h,\dfrac{2}{3}x^2y\left(15x-0,9y+6\right)\\ =\left(\dfrac{2}{3}x^2y.15x\right)-\left(\dfrac{2}{3}x^2y.0,9y\right)+\left(\dfrac{2}{3}x^2y.6\right)\\ =10x^3y-\dfrac{3}{5}x^2y^2+4x^2y\)

\(i,-\dfrac{3}{7}x^4\left(2,1y^2-0,7x+35\right)\\ =\left(-\dfrac{3}{7}x^4.2,1y^2\right)-\left(-\dfrac{3}{7}x^4.0,7x\right)+\left(-\dfrac{3}{7}x^4.35\right)\\ =-\dfrac{9}{10}x^4y^2+\dfrac{3}{10}x^5-15x^4\)

g: =x^2y*3xy^2-xy*3xy^2+xy^2*3xy^2+y^3*3xy^2

=3x^3y^3-3x^2y^3+3x^2y^4+3xy^5

h: =2/3x^2y*15x-2/3x^2y*0,9y+2/3x^2y*6

=10x^3y-0,6x^2y^2+4x^2y

i: =-3/7x^4*2,1y^2+3/7x^4*0,7x-3/7x^4*35

=-0,9x^4y^2+3/10x^5-15x^4

g)(x²y-xy+xy²+y³).3xy²

 =x²y.3xy²  -   xy.3xy²+   xy².3xy²   +   y³.3xy²

 =    3x³y³   -   3x²y³   +    3x²y⁴         +3xy⁵

h)2/3x²y(15x-0,9y+6)

=2/3x2y.15x     -        2/3x²y.0,9y   +     2/3x²y.6

=     10x³y        -         3/5x²y²          +    4x²y

i)-3/7x⁴(2,1y²-0,7x+35)

=   -3/7x⁴.2,1y²        +     3/7x⁴.0,7x      -      3/7x⁴.35

=        -9/10x⁴y²           +         3/10x⁵          -       15x⁴

\(a.x^3+12x^2+48x+64=x^3+3.4x^2+3.4^2x+4^3=\left(x+4\right)^3\)

Thay \(x=6\) vào \(\left(x+4\right)^3=\left(6+4\right)^3=10^3=1000\)

\(b,B=x^3-6x^2+12x-8=\left(x-2\right)^3\)

Thay \(x=22\) vào \(\left(x-2\right)^3=\left(22-2\right)^3=20^3=8000\)

\(c,C=x^3+9x^2+27x+27=x^3+3.3x^2+3.3^2x+3^3=\left(x+3\right)^3\)

Thay \(x=-103\) vào \(\left(x+3\right)^3=\left(-103+3\right)^3=\left(-100\right)^3=-1000000\)

\(d,D=x^3-15x^2+75x-125=x^3-3.5x^2+5^2.3x-5^3=(x-5)^3\)

Thay \(x=25\) vào \(\left(x-5\right)^3=\left(25-5\right)^3=20^3=8000\)

a) \(A=x^3+12x^2+48x+64\)

\(=x^3+3\cdot4\cdot x^2+3\cdot4^2\cdot x+4^3\)

\(=\left(x+4\right)^3\)

Thay \(x=6\) vào biểu thức A ta có:

\(\left(6+4\right)^3=10^3=1000\)

Vậy: ...

b) \(B=x^3-6x^2+12x-8\)

\(=x^3-3\cdot2\cdot x^2+3\cdot2^2\cdot x-2^3\)

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

Thay \(x=22\) vào biểu thức B ta có:

\(\left(22-2\right)^3=20^3=8000\)

Vậy: ...

c) \(C=x^3+9x^2+27x+27\)

\(=x^3+3\cdot3\cdot x^2+3\cdot3^2\cdot x+3^3\)

\(=\left(x+3\right)^3\)

Thay \(x=-103\) vào biểu thức C ta được:

\(\left(-103+3\right)^3=\left(-100\right)^3=-1000000\)

Vậy: ...

d) \(D=x^3-15x^2+75x-125\)

\(=x^3-3\cdot5\cdot x^2+3\cdot5^2\cdot x-5^3\)

\(=\left(x-5\right)^3\)

Thay \(x=25\) vào biểu thức D ta được:

\(\left(25-5\right)^3=20^3=8000\)

Vậy: ...

a: A=(x+4)^3

Thay x=6 vào A, ta được:

A=(6+4)^3=10^3=1000

b: B=(x-2)^3

Khi x=22 thì B=(22-2)^3=8000

c: C=(x+3)^3

Khi x=-103 thì C=(-103+3)^3=(-100)^3=-1000000

d: D=(x-5)^3

Khi x=25 thì

D=(25-5)^3=20^3=8000

câu 4 hình nhỏ quá 

Câu 5 : A

Câu 4: D - Vì 0% = 30%?

Câu 5: A

4. A (40%+30%+20%+10100%)

5. A

o: =-12:6*x^4:x=-2x^3

p: =(3:0,25)*(x^5:x^2)=12x^3

q: =1/2x^4:(-1/9x)+1/4x^3:1/9x+x:(-1/9x)

=-9/2x^3+9/4x^2-9

r: =-4x^2+2x+6

s: =(2x-1)^2/(2x-1)=2x-1

t: =(x-2)(2x-1)/(x-2)=2x-1

u: =(4x-3)(4x+3)/-(4x-3)=-(4x+3)=-4x-3

\(\text{≌₰⇴⩸⨙⩸※◡⨦}\)

a: 

b: Thời điểm 11h là nhiều khách nhất, 13h là ít khách nhất

c: Tổng số lượt khách là: 40+50+20+35+45=190(lượt)

Số lượt khách lúc 11h tăng: 50/40-100%=10/40=25%

Số lượt khách lúc 13h giảm: (50-20)/50=30/50=60%

a) \(\left(x-3\right)\left(x^2+3x+9\right)-x\left(x+2\right)\left(2-x\right)=1\)

\(\Leftrightarrow\left(x-3\right)\left(x^2+3x+9\right)+x\left(x+2\right)\left(x-2\right)=1\)

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

\(\Leftrightarrow x^3-27-x\left(x^2-2^2\right)=1\)

\(\Leftrightarrow x^3-27-x^3+4x=1\)

\(\Leftrightarrow4x-27=1\)

\(\Leftrightarrow4x=28\)

\(\Leftrightarrow x=7\)

b) \(\left(x+1\right)^3-\left(x-1\right)^3-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow\left[\left(x+1\right)-\left(x-1\right)\right]\left[\left(x+1\right)^2+\left(x-1\right)\left(x+1\right)+\left(x-1\right)^2\right]-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow2\left[\left(x+1\right)^2+\left(x^2-1\right)+\left(x-1\right)^2\right]-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow2\left[\left(x^2+2x+1\right)+\left(x^2-1\right)+\left(x^2-2x+1\right)\right]-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow2\left(x^2+2x+1+x^2-1+x^2-2x+1\right)-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow2\left(3x^2+1\right)-6\left(x-1\right)^2=-10\)

\(\Leftrightarrow6x^2+2-6\left(x^2-2x+1\right)=-10\)

\(\Leftrightarrow6x^2+2-6x^2+12x-6=-10\)

\(\Leftrightarrow12x-4=-10\)

\(\Leftrightarrow12x=-6\)

\(\Leftrightarrow x=-\dfrac{6}{12}=-\dfrac{1}{2}\)

\(a,\left(x-3\right)\left(x^2+3x+9\right)+x\left(x+2\right)\left(2-x\right)=1\\ \Leftrightarrow x^3-3x^2+3x^2-9x+9x-27+\left(x^2+2x\right)\left(2-x\right)-1=0\\ \Leftrightarrow x^3-3x^2+3x^2-9x+9x-27+2x^2-x^3+4x-2x^2-1=0\\ \Leftrightarrow x^3-x^3-3x^2+3x^2+2x^2-2x^2-9x+9x+4x=1+27\\ \Leftrightarrow4x=28\\ \Leftrightarrow x=7\)

\(b,\left(x+1\right)^3-\left(x-1\right)^3-6\left(x-1\right)^2=-10\\ \Leftrightarrow\left[\left(x+1\right)-\left(x-1\right)\right].\left[\left(x+1\right)^2+\left(x+1\right)\left(x-1\right)+\left(x-1\right)^2\right]-6\left(x^2-2x+1\right)=-10\\ \Leftrightarrow2.\left[\left(x^2+2x+1\right)+\left(x^2-1\right)+\left(x^2-2x+1\right)\right]-6x^2+12x-6=-10\\ \Leftrightarrow2.\left(3x^2+1\right)-6x^2+12x-6=-10\\ \Leftrightarrow6x^2-6x^2+12x=-10+6-2\\ \Leftrightarrow12x=-6\\ \Leftrightarrow x=-\dfrac{1}{2}\)

b: 4x^2+4x+1=(2x+1)^2

c: =(6x+1)^2

d: =(3x-4y)^2

e: =(1/2x+2y)^2

f: =-(x^2-10x+25)

=-(x-5)^2

g: =-(16a^4b^6+24a^5b^5+9a^6b^4)

=-a^4b^4(16b^2+24ab+9a^2)

=-a^4b^2(4b+3a)^2

h: =(5x)^2-2*5x*2y+(2y)^2

=(5x-2y)^2

i: =(5x^2)^2-2*5x^2*y+y^2

=(5x^2-y)^2