First simplify and then evaluate: (x + 2) 2 + (2x + 1) (2x-1) - 4x (x + 1), where x=- 2．

First simplify and then evaluate: (x + 2) 2 + (2x + 1) (2x-1) - 4x (x + 1), where x=- 2．

The original formula = x2 + 4x + 4 + 4x2-1-4x2-4x = x2 + 3,
When x=-
2, the original formula = 2 + 3 = 5

The result of X Cubic - 2x 2 + X (x > 1) under the root sign is

A:
X>1
√(x³-2x²+x)
=√[(x²-2x+1)x]
=√[x(x-1)²]
=(x-1)√x

When x > 2, the root number (X-2) 2 - the root sign (1-2x) 2 is reduced

Because x ＞ 2, so X-2 ＞ 0,1-2x ＜ 0, so the root sign (X-2) 2 - radical sign (1-2x) 2 = (X-2) - [- (1-2x)] = X-2 - [2x-1] = x-2-2x + 1 = - X-1 if you don't understand this question, please click "accept as satisfied answer" if you have other questions, please adopt this question and then

Simplify X-1 / x? - 2x + 1 △ 1 / x? - 1, where x = radical 2-1

x-1/x²-2x+1÷1/x²-1
=(x-1)/(x-1)^2*(x+1)(x-1)
=x+1
=Radical 2-11
=Radical 2

When x is taken, the fraction x + 1 / 2x + 1 is meaningful

If it is a fraction (x + 1) / (2x + 1), then 2x + 10, X-1 / 2
If the fraction x + 1 / (2x) + 1, then 2x0, x0

When x______ Fraction 2x + 1 2x − 4 makes sense

According to the meaning of the title, 2X-4 ≠ 0,
The solution is x ≠ 2
2

When X -, the fraction 3 / 2x-5-1 / x + 2 makes sense When X -, the fraction 3 / 2x-5-1 / x + 2 makes sense

The fraction is meaningful, and the denominator is not 0, so 2x-5 and X + 2 are not 0, so x is not equal to - 2 and 2.5

If fraction 1 X2 − 2x + m no matter what value x is, the value range of M is () A. m≥1 B. m＞1 C. m≤1 D. m＜1

Fraction 1
X2 − 2x + m no matter what value x takes, its denominator must not be equal to 0,
The denominator is sorted into (a + b) 2 + K (k > 0)
（x2-2x+1）+m-1=（x-1）2+（m-1），
Because the value of X (x2-2x + 1) + M-1 = (x-1) 2 + (m-1) is not equal to 0,
So M-1 > 0, that is, M > 1,
Therefore, B

It is known that the maximum value of the quadratic function y = ax squared + BX + C is - 3a, and its image passes through (- 1, - 2) and (1,6), and finds a, B, C

y=ax^2+bx+c
=a(x^2+bx/a+b^2/4a^2)+c-b^2/4a
=a(x+b/2a)^2+c-b^2/4a
Because there is a maximum, so a

Given that the quadratic function y = ax ^ 2 + 2x + 3A has the maximum value - 2, find the value of A

((4*a*3a)-4)/4*a=-2
A = - 1 or 1 / 3
And because there is a maximum, so a