Junior high school math questions are asked to be answered. Junior high school math problems, ask fo

This is the last fill-in-the-blank in the 2011 Chengdu High School Entrance Examination Mathematics Paper B. A lot of people get the answer wrong.

1) Method: "When x < 0, y decreases with the increase of x" pushes the k>0 intersection problem into a system of equations problem, which obtains:

Let p be (a,b). It can be obtained: ab=2k, a + root number 3k = b, a square + b square = 7, and the solution is: k = 3 7 (rounded).

2) Conclusion: There are 0.

From the meaning of the title, we can know that k is greater than 0, synthesis, y=2k x, and y=x + root number 3k can be solved to get two solutions represented by x represented by k, and then let the point through p point be (because op is the root number 7, list the sub-formula, and then substitute the equation of x about k, and the k value can be solved.

Then determine how much value k has.

I multiply the root number by k to get k=1Because the area of each point perpendicular to the xy axis on the inverse function is a proportionality factor.

Let p coordinates be (a,b),ab=2k,a2+b2=7."k is used to represent a, bSubstitute it into the function one more time. Find two and round off the negative values.

I apologize for writing quickly and possibly making mistakes.

Because when x is 0, y decreases as x increases.

Then we know that k 0 lets the coordinates of p be (x,y), and |op|= root number 7 then there is x square + y square = 7

If the point p is on the inverse proportional function, there is xy=2k

and y=x+root3k

It is obtained by the square root formula, 3k square + 4k-7 = 0

The solution is k=1 or k=-7 3 (rounded).

Therefore k = 1

Cough... I can't do math in junior high school. Tears run.

One, the easiest way is the ** method, of course the algebraic method can also be used to judge the size of 7k by better 11k.

abc is an equilateral blind triangle, ab=6, the moving point o starts from the point a on the edge of abc and moves at a constant speed along the route of a c b a, the velocity without leakage is 1 length unit per second, and the circle with o as the center and radius is tangent to the edge of abc for the second time in the process of motion is the second after the departure search.

The two purchases add up to four items of A, B, and C, and the silver round can be divided by four.

Original = (3a +3a+1) a

(a+1) -a ] a uses the sum cube formula

(a+1)/a]³-1 （1）

a=³√4+³√2+³√1

Multiply both sides by 2

This results in 2a= 8+ 4+ 2 =2+ 4+ 2 =2+( 4+ 2+ 1)- 1

Compare with a= 4+ 2+ 1.

2a=2+a-1=a+1

Get: (a+1) a= 2.

Brought in (1), the original formula = [(a+1) a] 3-1 = ( 2) -1 = 2-1 = 1

a*Cubic root number 2=2 + Cubic root number 4 + root number Cubic 2=1+a

a=1 (cube root number 2-1).

The equation = (3a 2+3a+1) a 3=((a+1) 3-a 3) a 3=((a+1) a) 3-1=(1+cube root number 2-1) 3-1=2-1=1

Let x=2 (1 3), so 1 a = x-1. (formula: b 3-1 = (b -1) (b 2 + b + 1)).

Substituting the original equation:

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

(a+b) 3=a 3+3a 2b+3ab 2+b 3(1+1 a) 3=1+3 a+3 a 2+1 a 3 so 3 a+3 a 2+1 a 3=(1+1 a) The equation of 3-1a is an equal column, and the proportion is the middle term, so a=1 (2 (1 3)-1).

Substitution will find the answer as 1

Using the cubic method of (x+1) to simplify the original formula, and then using the formula for summing the proportional series with a common ratio of (one-third of the power of 2), we can get a by using the simple conversion, and the answer should be 1.

△ace∽△efd（∠c=∠d，∠cae=∠def=135º－∠aec）

Let the similarity ratio be k

The area is equal k =1

k=±1∵k＞0∴k=1

ace≌△efd

ac=de=3

ce=4√2－3

Good luck, you should have solved it.

State and promotion and housing purchase plan country and national macro Huang Jiguang.