The roots x0 and x0 of equation log2 ^ (x + 2) = 4x belong to (k, K + 1), and the value of K is obtained

The roots x0 and x0 of equation log2 ^ (x + 2) = 4x belong to (k, K + 1), and the value of K is obtained

Let f (x) = log2 (x + 2) - 4x
f(0)=1>0 f(1)=log2(3)-4=log2(3)-log2(16)=log2(3/16)

The price of a certain commodity has been reduced by 10% for two consecutive times. The current price is 162 yuan. How much is the original price of this commodity?

200 yuan, it should be

Let x0 be a solution of the equation 4-x ^ 2 = log2, if x0 ∈ (k, K + 1) k ∈ Z, find K

k=1

The original price of a commodity is a yuan. After two successive price cuts of 10%, the price is increased by 20%. How much is the current price of the commodity?

0.972a
X=a*0.9*0.9*1.2=0.972a

If the roots of the equation lgx = 4-2x x ∈ (k, K + 1), K ∈ Z, then K=______ ．

Draw the corresponding function image on both sides of the equation: lgx = 4-2x, as shown in the figure. From the figure, we know that their intersection point x0 is in the interval (1, 2), so k = 1. So the answer is: 1

The price of a commodity has been reduced from a yuan to B yuan for two consecutive times. Suppose the average percentage of each reduction is x, then the equation is correct

a（1-x）^2=b

If x0 is the root of the equation lgx-1 / x = 0, then x0 belongs to the interval?
A.(0,1] B (1,10] C(10,100] D (100,+∞）
By the way, how to solve the problem

F (x) = lgx-1 / X is an increasing function with only one root at most
f(1)=-10
So the only root is (1,10)
Choose B

The original price of a drug is 36 yuan / box. After two successive price cuts, the price is 25 yuan / box. Suppose the average percentage of each price cut is X. according to the equation listed in the title, the correct price is ()
A. 36（1-x）2=36-25B. 36（1-x）2=25C. 36（1-2x）=25D. 36（1-x2）=25

After the first price reduction, the price is 36 × (1-x). After two successive price reductions, the price is reduced by X on the basis of the first price reduction, which is 36 × (1-x) × (1-x). Then the equation listed is 36 × (1-x) 2 = 25

Let x0 be the solution of the equation lgx = - x + 4, then the interval of x0 is (k, K + 1), and K belongs to Z, then K=

Let f (x) = lgx + x-4
Obviously, f (x) increases monotonically
f(3)=lg3-10
So x0 ∈ (3,4)
So k = 3

After two consecutive price cuts in April and may, the price of a mobile phone of a certain brand has dropped from 3200 yuan to 2500 yuan______ ．

According to the meaning of the question: the price after two price cuts is 3200 (1-x) 2 = 2500, so the answer is: 3200 (1-x) 2 = 2500