There are 20 peaches in one basket. They are divided among four children, five for each. There are five left in the basket. What's the matter? (it will be added if it's OK)

There are 20 peaches in one basket. They are divided among four children, five for each. There are five left in the basket. What's the matter? (it will be added if it's OK)

Because a man took a basket with his peach in it

A + A + A = 9
（ ）+（ ）= 18
（ ）+ A = （ ）
How to fill in the brackets?

A + A + A = 9
（ 9 ）+（9 ）= 18
（ 1）+ A = （4）

Square of X + square of Y + square of Z - 2x + 4y-6z + 14 = 0, find the value of 3x + 4Y + 5Z

Square of X + square of Y + square of Z - 2x + 4y-6z + 14 = 0
(x-1)^2+(y+2)^2+(z-3)^2=0
So, x = 1, y = - 2, z = 3
The value of 3x + 4Y + 5Z = 3x1-4x2 + 5x3 = 10

The equation of circle 1 is x ^ 2 + y ^ 2-2 = 0, and the equation of circle 2 is x ^ 2 + y ^ 2-8x + 10 = 0. The tangent lengths from the moving point P to circle 1 and circle 2 are equal
Then the trajectory equation of the moving point P is?

O1 (0,0) R1 = radical 2, O2 (4,0) R2 = 2,
The tangent length is equal, so two right triangles can be formed: | po1 | ^ 2 + 2 = | po1 | ^ 2 + 4
|PO1|^2=|PO1|^2+2
Let P (x, y) be taken into the calculation and simplified

(x + 14) divide by 5 = 8.6 how to calculate! Fast, add high score!

(x + 14) divided by 5 = 8.6
x+14=8.6x5
x+14=43
x=43-14
x=29

The triviality + 6x-10 of the algebraic formula - x is known. It is proved by the collocation method that no matter what x is, the value of the square + 6x-10 of the algebraic formula - x is always negative

-X & # 178; + 6x-10 = - (X & # 178; - 6x + 9) - 1 = - (x-3) &# 178; - 1 is obviously always less than 0, which is negative

If a and B are reciprocal and a fifth of a equals x of B, then x equals X

a = 1/5
b = 5
5x = a/5
x = a/25
= 1/5

It is known that the solutions of the equations {2x + 3Y = k, 3x-4y = K + 11 about X and y satisfy the equation 5x-y = 3. There are four solutions to find the value of K

Method 1: solve the equations 2x + 3Y = k, 3x-4y = K + 11, use K to express x, y, and then bring in 5x-y = 3 to find K
Method 2: 2x + 3Y + 3x-4y = K + K + 11 = 3, 2K = - 8, k = - 4

It is known that the image of function y = f (x) is continuous, and there is a unique zero point in the interval (0.2, 0.3). If we use dichotomy to find the zero point, the accuracy is 0.0001, then the number of times to divide the interval (0.2, 0.3) is at least ()
A. 7 times B. 8 times C. 10 times D. 11 times

The length of the interval (0.2, 0.3) is equal to 0.1, and the accuracy is 0.0001. Therefore, the length of the interval needs to be reduced at least 11000 times. Each time, the interval length becomes 12. (12) 9 = 1512 ＞ 11000, (12) 10 = 11024 ＜ 11000. Therefore, the number of times to divide the interval (0.2, 0.3) should be at least 10 times, so C

It is known that the two intersection points of parabola y = - x2 + BX (b > 0) and X axis and the triangle surrounded by the vertex are isosceles right triangles

The analytic formula of ∵ parabola is y = - x2 + BX (b > 0), the vertex of ∵ parabola (B2, B24), the intersection of ∵ parabola y = - x2 + BX (b > 0) and X axis, and the triangle surrounded by the vertex are isosceles right triangle, ∵ B2 = B24 (b > 0). The solution is b = 2