Given that the root of the equation KX + 1 = 2x-1 is a positive number, then the value range of K is______ ．

∵ the root of equation KX + 1 = 2x-1 is a positive number, ∵ x = − 2K − 2 ＞ 0, that is, K-2 ＜ 0, the solution is k ＜ 2

The equation f (x) = - 5 / 2x + B of X has two unequal real roots in the interval (0,2)

Hyperbola, the intersection points of the two curves and the Y axis are on (0,2). Then - 5 / 2x + B = 0, then x = 5B / 2. So 5B / 2 belongs to (0,2), and B belongs to (0,4 / 5)
The original meaning of the title is hyperbola, isn't it

There are always two symmetries on the parabola y 2 = 4x with respect to the straight line y = k x + 3

Let B and C be symmetric with respect to the line y = KX + 3, so let the BC equation of the line be x = - KY + m, and substitute y2 = 4x to get Y2 + 4ky-4m = 0. Let B (x1, Y1), C (X2, Y2), then If the midpoint of BC is m (x0, Y0), then Y0 = Y1 + Y22 = - 2K, x0 = 2k2 + M. ∵ the point m (x0, Y0) is on the straight line L, ∵ 2K = K (2k2 + m) + 3, ∵ M = - 2K3 + 2K + 3K. The intersection of BC and parabola is at two different points, ∵ Δ= 16k2 + 16m > 0

Who has a relatively simple encounter problem, profit and discount problem,
Say the upper half is OK, best all. Because I didn't share, so there's no reward. Sorry

If the distance from the moving point P to the point (1,1) is equal to the distance from it to the y-axis, then the trajectory equation of the moving point P is

This is the definition of parabola. The focus is (1,1), and the collimator is the y-axis
P is the distance from the focus to the guide line, P = 1
So when (0.5,0) is taken as the origin, the parabolic equation is y '^ 2 = 2x'
That is, when the original coordinate (0,0) is the origin, the parabolic equation is y ^ 2 = 2 (x-0.5)

A simple factorization
2x^3-x^2-1
The answer is group decomposition, but I still don't understand

x^2(x-1)+x^3-1 =x^2(x-1)+(x-1)(x^2+x+1) =(x-1)(2x^2+x+1)

How many days are there from July 14, 2011 to September 5, 2012

59 weeks 6 days
419 days in total

1. What is the volume of water after a 100m3 ice block is completely melted into water, regardless of the vaporization of water in the melting process?
2. An iron ball with a mass of 316g and a volume of 1250px3
(1) is the iron ball hollow or solid?
(2) if it is hollow, what is the volume of the hollow part?
(3) if the hollow part is filled with water, what is the total mass of the ball?
The volume of an iron ball is 50 cubic centimeters

1. V ice = 100cm ^ 3 = 1 × 10 ^ - 4m ^ 3
Known ρ ice = 0.9 × 10 ^ 3kg / m ^ 3
So m ice = ρ ice V ice = 0.9 × 10 ^ 3kg / m ^ 3 × 10 ^ - 4m ^ 3 = 0.09kg
∵ m water = m ice
Ψ V water = m water / ρ water = 0.09kg/1 × 10 ^ 3kg / m ^ 3 = 9 × 10-5m ^ 3 = 90cm ^ 3
2. The volume is 1250px3. Is it 1250cm3? I calculate it as 1250cm3. If not, please change the data
(1) According to ρ = m / V, the volume of iron in the iron ball is as follows:
V1 = M1 / ρ Fe = 316g / 7.9g/cm ^ 3 = 40cm ^ 3
∵V1＜V,
The ball is hollow;
(2) Volume of hollow part:
Vnong = v-v1 = 1250cm3-40cm3 = 1210cm3;
(3) When the hollow part is filled with water, the water quality is as follows:
M2 = ρ water V air = 1g / cm3 × 1210cm3 = 1210g,
The total mass of the ball is as follows:
m=m1+m2=316g+1210g=1526g．

The National Day in 2007 is Monday. What day is the last day in October 2007?

1+28=29
So the 31st is Wednesday

The concept of the formula of multiplicative distributive law

(a+b)c=ac+bc

Given that the root of the equation KX + 1 = 2x-1 is a positive number, then the value range of K is______ ．