123456789 = 100 use two minus signs and a plus sign to make the equation hold except 123-45-67 + 89

123456789 = 100 use two minus signs and a plus sign to make the equation hold except 123-45-67 + 89

123456789 = 100 use two minus signs and a plus sign to make the equation true
123-45-67+89=100

Given that the equation (A-2) ^ 2 * x ^ 2-ax = x ^ 2-1 about X is a quadratic equation of one variable, then the value range of a is?
For example, the quadratic power of difference multiplied by the quadratic power of x minus ax equals to the quadratic power of X-1
Write down the steps, analysis and test points

It is known that the equation (A-2) ^ 2 * x ^ 2-ax = x ^ 2-1 about X is a quadratic equation of one variable
That is [(A-2) &# 178; - 1] X & # 178; - ax + 1 = 0
It only needs (A-2) &# - 1 ≠ 0
That is, (A-2 + 1) (a-2-1) ≠ 0
(a-1)(a-3)≠0
The solution is a ≠ 1 or a ≠ 3

3 () 3 () 3 () 3 () = 5. Multiplication, division, addition and subtraction can be filled in brackets

1-5 = 0.2, 5-0.2 = 4.8, 4.8 * 5 = 24 or 5 * [5 - (1 / 5)]

What do you mean by the square of B plus 4ac
What about the square of 4ac-b in 4A

It should be the square of B minus 4ac. It is the discriminant of the root. What does the square of B plus 4ac mean depends on the specific situation
The square of 4ac-b in 4a is the best solution

What is the correlation coefficient r of one variable linear regression equation and what is its significance?

R = (sum sign (xi-x average) (yi-y average) / root sign (sum sign (xi-x average) ^ 2 sum sign (yi-y average) ^ 2) (sum is from 1 to n)
R is generally used to measure the degree of linear correlation

If the area of the figure enclosed by two curves y = x2 and y = cx3 is 1.5, the value of C will be added if the answer is good
C is greater than zero, and it is C value! The area tells you, it is 3/2. Hope to answer awesome!

The intersection of two curves is x 1 = 0, x 2 = 1 /. C. only x and y can be obtained
The definite integral is from 0 to 1 / C, and the original function is 1 / 3x3-c / 4 * X4,
Find C = 1 / 6 under the root of the third power (if the area is 1 / 2)

Thinking about 32 pages of sixth grade mathematics exercise book
For a square piece of paper, use half of it for the first time, use half of it for the second time, use half of it for the third time, and use a fraction of it for the third time

Let the square drawing be 1, 1 / 2 be removed in the first time, 1 / 4 be removed in the second time, and 1 / 8 be removed in the third time,

It is known that the center of the ellipse is at the origin of the coordinate, and the focus is on the x-axis. One of its focuses is f, M is any point on the ellipse, and the maximum and minimum of | MF |
It is known that the center of the ellipse is at the origin of the coordinate, the focus is on the x-axis, one of its focuses is f, M is any point on the ellipse, the geometric mean of the maximum and minimum of | MF | is 2, there are symmetric points M1 and M2 on the ellipse with y = x as the axis, and | m1m2 | = four-thirds root sign 10. The equation of the ellipse is obtained

Mathematics calculation of grade four in primary school
45×35+36×54+99×64
9999×222+3333×334

(1) Original formula = 45 * 35 + (35 + 1) * 54 + 99 * 64 = 45 * 35 + 54 * 35 + 54 + 99 * 64 = (45 + 54) * 35 + 54 + 99 * 64 = 99 * 35 + 54 + 99 * 64 = 99 * (35 + 64) + 99-45 = 99 * (99 + 1) - 45 = 9900-45 = 9855 (2) original formula = 3 * 3333 * 222 + 3333 * 334 = 666 * 3333 + 334 * 3333 = (666 + 334) * 3333 = 1000 * 3333 = 3

It is known that the system of equations {x ^ 2 + y = 9, 2x-y = a {x ^ 2 + y = 9, 2x-y = a} about X and y has no real solution, so the value range of a is obtained
ditto

y=2x-a
So x & sup2; + 2x-a = a
X & sup2; + 2x-2a = 0 no real solution
The discriminant is less than 0
4+8a