There are 102 students in two classes in Grade 6 of a primary school. If one eighteenth of the total number of students is transferred from Class A to class B, then the number of students in the two classes is equal. How many students are there in class a

There are 102 students in two classes in Grade 6 of a primary school. If one eighteenth of the total number of students is transferred from Class A to class B, then the number of students in the two classes is equal. How many students are there in class a

If there are x people in class A, then there are 102-x people in class B
（1-1/18）X=102-X+1/18X
17/18X+X-1/18X=102
34/18X=102
X=54

The ratio of students in class A and class B is 5:4. If nine students are taken from class B, the number of students in class A is two-thirds more than that in class B. how many students in class B?

There are 5x students in class A and 4x students in class B
(4x-9)×（2/3+1）=5x
x=9
9 × 4-9 = 27 persons
A: there are 27 people in class B at this time

Finding the derivative of the function y = cosx ^ 4

y=cosu
If u = x ^ 4, then u '= 4x & # 179;
So y '= - sinu * u'
=-4x³sin(x^4)

The more, the better,

7(2x-1)-3(4x-1)=4(3x+2)-1;
(5y+1)+ (1-y)= (9y+1)+ (1-3y);
20%+(1-20%)(320-x)=320×40%
2(x-2)+2=x+1
2(x-2)-3(4x-1)=9(1-x)
x/3 -5 = (5-x)/2
2(x+1) /3=5(x+1) /6 -1
(1/5)x +1 =(2x+1)/4
(5-2)/2 - (4+x)/3 =1
x/3 -1 = (1-x)/2
(x-2)/2 - (3x-2)/4 =-1
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2
2(x-2)-3(4x-1)=9(1-x)
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2
2(x-2)+2=x+1
1.7(2x-1)-3(4x-1)=4(3x+2)-1
2.(5y+1)+ (1-y)= (9y+1)+ (1-3y)
3.[ (- 2)-4 ]=x+2
4.20%+(1-20%)(320-x)=320×40%
5.2(x-2)+2=x+1
6.2(x-2)-3(4x-1)=9(1-x)
7.11x+64-2x=100-9x
8.15-(8-5x)=7x+(4-3x)
9.3(x-7)-2[9-4(2-x)]=22
10.3/2[2/3(1/4x-1)-2]-x=2
11.5x+1-2x=3x-2
12.3y-4=2y+1
13.87X*13=5
14.7Z/93=41
15.15X+863-65X=54
16.58Y*55=27489
17.2（x+2）+4=9
18.2(x+4)=10
19.3(x-5)=18
20.4x+8=2(x-1)
21.3(x+3)=9+x
22.6(x/2+1)=12
23.9(x+6)=63
24.2+x=2(x-1/2)
25.8x+3(1-x)=-2
26.7+x-2(x-1)=1
27.x/3 -5 = (5-x)/2
28.2(x+1) /3=5(x+1) /6 -1
29.(1/5)x +1 =(2x+1)/4
30.(5-2)/2 - (4+x)/3 =1
15x-8(5x+1.5)=18*1.25+x
3X+189=521
4Y+119=22
3X*189=5
8Z/6=458
3X+77=59
4Y-6985=81
87X*13=5
7Z/93=41
15X+863-65X=54
58Y*55=27489
1. 2(x-2)-3(4x-1)=9(1-x)
2. 11x+64-2x=100-9x
3. 15-(8-5x)=7x+(4-3x)
4. 3(x-7)-2[9-4(2-x)]=22
5. 3/2[2/3(1/4x-1)-2]-x=2
6. 2(x-2)+2=x+1
7. 0.4(x-0.2)+1.5=0.7x-0.38
8. 30x-10(10-x)=100
9. 4(x+2)=5(x-2)
10. 120-4(x+5)=25
11. 15x+863-65x=54
12. 12.3(x-2)+1=x-(2x-1)
13. 11x+64-2x=100-9x
14. 14.59+x-25.31=0
15. x-48.32+78.51=80
16. 820-16x=45.5×8
17. (x-6)×7=2x
18. 3x+x=18
19. 0.8+3.2=7.2
20. 12.5-3x=6.5
21. 1.2(x-0.64)=0.54
22. x+12.5=3.5x
23. 8x-22.8=1.2
24. 1\ 50x+10=60
25. 2\ 60x-30=20
26. 3\ 3^20x+50=110
27. 4\ 2x=5x-3
28. 5\ 90=10+x
29. 6\ 90+20x=30
30. 7\ 691+3x=700
1 2x-10.3x=15
2 0.52x-(1-0.52)x=80
3 x/2+3x/2=7
4 3x+7=32-2x
5 3x+5(138-x)=540
6 3x-7(x-1)=3-2(x+3)
7 18x+3x-3=18-2(2x-1)
8 3(20-y)=6y-4(y-11)
9 -(x/4-1)=5
10 3[4(5y-1)-8]=6
3X+5X=48 14X-8X=12 6*5+2X=44
20X-50=50 28+6X=88 32-22X=10
24-3X=3 10X*（5+1）=60 99X=100-X
X+3=18 X-6=12 56-2X=20
4y+2=6 x+32=76 3x+6=18
16+8x=40 2x-8=8 4x-3*9=29
8x-3x=105 x-6*5=42 x+5=7
2x+3=10 12x-9x=9 6x+18=48
56x-50x=30 5x=15 78-5x=28
32y-29=3 5x+5=15 89x-9=80
100-20x=20 55x-25x=60 76y-75=1
23y-23=23 4x-20=0 80y+20=100
53x-90=16 2x+9x=11 12y-12=24
80+5x=100 7x-8=6 65x+35=100
19y+y=40 25-5x=15 79y+y=80
42x+28x=140 3x-1=8 90y-90=90
80y-90=70 78y+2y=160 88-x=80
9-4x=1 20x=40 65y-30=100
51y-y=100 85y+1=-86 45x-50=40
3X+18=52 x=34/3
4Y+11=22 y=11/4
3X*9=5 x=5/27
8Z/6=48 z=36
3X+7=59 x=52/3
4Y-69=81 y=75/4
8X*6=5 x=5/48
7Z/9=4 y=63/7
15X+8-5X=54 x=4.6
5Y*5=27 y=27/40
8x+2=10 x=1
x*8=88 x=11
y-90=1 y=91
2x-98=2 x=50
6x*6=12 x=1/3
5-6=5x x=-1/5
6*x=42 x=7
55-y=33 y=22
11*3x=60 x=20/11
8-y=2 y=-6
1.x+2=3
2.x+32=33
3.x+6=18
4.4+x=47
5.19-x=8
6.98-x=13
7.66-x=10
8.5x=10
9.3x=27
10.7x=7
11.8x=8
12.9x=9
13.10x=100
14.66x=660
15.7x=49
16.2x=4
17.3x=9
18.4x=16
19.5x=25
20.6x=36
21.8x=64
22.9x=81
23.10x=100
24.11x=121
25.12x=144
26.13x=169
27.14x=196
28.15x=225
29.16x=256
30.17x=289
31.18x=324
32.19x=361
33.20x=400
31.21x=441
32.22x=484
33.111x=12321
34.1111x=1234321
35.11111x=123454321
36.111111x=12345654321
37.46/x=23
38.64/x=8
39.99/x=11
40.1235467564x=0
41.2x+1= -2+x
42.4x-3(20-x)=3
43.．-2(x-1)=4
44.3X+189=521
45.4Y+119=22 5
46.3X+77=59
47.4Y-6985=81
48.X=0.1
49.5X=55.5
50.Y=50-85

Finding the general solution of differential equation y '' + y '= x ^ 2 + cosx

The homogeneous characteristic equation R ^ 2 + r = 0, r = 0, r = - 1, so the homogeneous general solution is y = C1 + c2e ^ (- x). The non-homogeneous is divided into two parts, y '' + y '= x ^ 2 and y' '+ y' = cosx. Let the first part of the special solution be Y1 = ax ^ 4 + BX ^ 3 + CX ^ 2 + DX + ey '= 4ax ^ 3 + 3bx ^ 2 + 2cx + dy' '= 12x ^ 2 + 6bx + 2c to get 12x ^ 2 + 6bx + 2C + 4ax ^ 3 + 3bx ^ 2 + 2cx +

Sequence - 1, 85, - 157249 A general formula of is______ ．

Sequence - 1, 85, - 157249 It can be written as − 33, 85, - 157249 Furthermore, it can be written as − (1 + 1) 2 − 12 × 1 + 1, (2 + 1) 2 − 12 × 2 + 1, − (3 + 1) 2 − 12 × 3 + 1, (4 + 1) 2 − 12 × 4 + 1 So a general formula is: an = (− 1) n (n + 1) 2 − 12n + 1, so the answer is: an = (− 1) n (n + 1) 2 − 12n + 1

Fill in the box with 9 numbers 123456 to make the formula true
【1】（ ）÷（ ）×（ ）＝（ )( )
( )＋（ ）－（ ）＝（ ）
【2】（ ）（ ）（ ）（ ）×（ ）＝（ ）（ ）（ ）（ ）

【1】（ 6）÷（3 ）×（ 9）＝（1 )( 8)
( 4)＋（ 5）－（2 ）＝（7 ）
【2】（ 1）（ 9）（6）（ 3）×（ 4）＝（ 7）（8）（5）（ 2）

In the rectangular coordinate system xoy, the straight line L passes through the point P (0.1 / 2) and the inclination angle is 150 degrees. The coordinate system is established with o as the pole and the positive half axis of X axis as the polar axis
The parameter equation of circle C is p ^ 2 + 2pcos angle = 0
Finding the parameter equation of L and the rectangular coordinate equation of circle C

The parameter equation of L is:
x=tcos150°=-t√3/2,
y=1/2+tsin150°=1/2+t/2.
The general equation is y = (- √ 3 / 3) x + 1 / 2,
The polar equation is psina = (- √ 3 / 3) pcosa + 1 / 2
The rectangular coordinate equation of circle C is x ^ 2 + y ^ 2 + 2x = 0

It is known that the center of the ellipse is at the origin, the axis of symmetry is the coordinate axis, the eccentricity is 0.6, and the sum of the major axis and minor axis is 36
The answer is x ^ 2 / 100 + y ^ 2 / 64 = 1 or x ^ 2 / 64 + y ^ 2 / 100 = 1

e=c/a=0.6
c=0.6a
b²=a²-c²=0.64a²
b=0.8a
2a+2b=36
So a + B = 18
So a = 10, B = 8
So x & sup2 / 100 + Y & sup2 / 64 = 1 or X & sup2 / 64 + Y & sup2 / 100 = 1

When removing the brackets, when the front of the brackets is "-", after removing the brackets, the symbols in the brackets should be changed (), the symbols in the brackets () or the symbols of a certain item, instead of being forgotten
If the sign of other items is changed, if the number factor is in front of the bracket, the multiplication distribution law can be used to multiply the number and the items in the bracket respectively, and then remove the bracket, so as to avoid mistakes; the result of integral simplification does not contain () and ()

It seems that the problem looks a bit awkward!