When I read a fairy tale book, I read two fifths of the whole book in the first week and 25% of the whole book in the second week. There are still 70 pages left. How many pages are there in this book The first answer is scored!

2 out of 5 equals 8 out of 20, 25% equals 5 out of 20, and the remaining 70 pages are: 1 - 8 out of 20 - 5 out of 20 = 7 out of 20
This book has: 70 divided by 7 times 20 = 200 (pages)

Xiao Lan read a book. On the first day, she read one sixth of the whole book. On the second day, she read one fifth of the whole book, which is exactly 60 pages. How many pages did she read on the first day?

Sixty divided by one fifth times one sixth = three hundred times one sixth = fifty (page)

Xiaolan read a book. On the first day, she read one sixth of the whole book. On the second day, she read one fifth of the whole book, which is exactly 60 pages. How many pages did she read on the first day

Did you read 60 pages the next day, or did you read 60 pages in two days
1/5x=60,x=300,300*1/6=50
I read 50 pages on the first day

The minimum value of the function y = x ^ 3-4x in the interval [- 2,3] is?

y′=3x^2-4=0
x=±√3/2
The extreme point on the function interval is the endpoint or the point with derivative 0
f（-2）=0
f（-√3/2）=-3√3/8+2√3＞0
f（√3/2）=3√3/8-2√3=-13√3/8
f（3）=15
In conclusion, when x = √ 3 / 2, the function has a minimum value of - 13 √ 3 / 8
If you don't understand this question, you can ask,

Cut a square cardboard with a side length of 40cm and fold it into a cuboid box (the thickness of the cardboard is ignored). As shown in the figure, if you cut a square of the same size at each corner of the square cardboard, fold the rest into a long square box without cover
① If the side length of the cut square is 9cm, calculate the volume of the rectangular box
② If the side length of the cut square is 10cm, calculate the side area of the rectangular box
(2) If you cut some rectangles around the square cardboard (that is, at least one edge of the cut rectangle is on the edge of the square cardboard), fold the rest into a rectangular box with a cover. If the length of the rectangular box is 15, the width is 10, and the height is 5, calculate the surface area of the rectangular box

①（40-9*2）*（40-9*2）*9=4356
②10*（40-2*10）*4=800
（2）2*（15*10+10*5+5*15）=550

If s is the distance, V is the speed and t is the time, then the formula for calculating the distance can be written
s=vt?

s=vt
Your answer is correct

Solve equation 1.7 (x + 0.69) = 2.3x x =?

1.7（x+0.69）=2.3x
1.7x+1.173=2.3x
2.3x-1.7x=1.173
0.6x=1.173
x=1.173/0.6
x=1.955

The angle of the center of the cone and the total area of the cone
The diameter of the lower side of the cone is 80 cm and the length of the generatrix is 90 cm

Perimeter of bottom surface = diameter * Π = 80 Π (CM),
Bottom area = radius * radius * Π = 40 * 40 * Π = 1600 Π (square centimeter),
The side view is fan-shaped, arc length = bottom circumference = 80 Π (CM), fan-shaped radius = generatrix length = 90 cm,
The sector area of the side expanded view is equal to arc length * sector radius / 2 = 80 Π * 90 / 2 = 3600 Π (square centimeter),
The center angle of the sector: 360 degrees = the area of the sector: the area of the complete circle expanded on the side,
Center angle of sector = sector area * 360 degrees / full circle area of side expansion
=3600 Π * 360 degrees / (90 * 90 Π),
=160 degrees;
The total area of the cone = the area of the base + the area of the sector in the side view
=1600∏+3600∏
=5200 square centimeters,

Let f (x) = log take 2 as base, X-1 / 1-ax as odd function, a as constant
(1) Find the value of a (2) prove that f (x) increases monotonically in the interval (1, positive infinity) (3) if for every x value in the interval [3,4], the inequality f (x) > m-2 to the x power [x power on 2] holds, and find the value range of real number M

(1) F (x) is an odd function
∴f(-x)=log2^[(-x-1)/(1+ax）]=-log2^[(x-1)/(1-ax)]
∴（-x-1)/(1+ax)=[(x-1）/(1-ax)^(-1)
It is reduced to: (a ^ 2-1) x ^ 2 = 0
a=±1
(2) Let x2 > X1 > 1
Then f (x2) - f (x1) = log2 ^ [(x2-1) / (1-ax2)] - log2 ^ [(x1-1) / (1-ax1) = log2 ^ {[(x2-1) / (1-ax2)] / [(x1-1) / (1-ax1)}
log2^[(x2-1)(ax1-1）]/[ax2-1)(x1-1)]
∵x2>x1>1,∴x2-1>0,x1-1>0；ax2-1>1,ax1-1>1；(x2-1)/(x1-1)>1
That is: F (x2) > F (x1)
The monotone increase of F (x) over x ∈ (1, + ∞)

Properties of absolute value inequality
For any real numbers a (a ≠ 0) and B, the inequality │ a ＋ B │ ＋ A-B │ ≥ a │ (│ X-1 │ ＋ X-2 │) holds. Find the value range of X

Triangular inequality, | a + B | + | A-B | > = | a + B + A-B | = | 2A |, that is to say, only | X-1 | + | X-2 is needed|

When I read a fairy tale book, I read two fifths of the whole book in the first week and 25% of the whole book in the second week. There are still 70 pages left. How many pages are there in this book The first answer is scored!