How to do (x + 1) (square of X - x + 1) + (x - 2) (square of X + 2x + 4)

How to do (x + 1) (square of X - x + 1) + (x - 2) (square of X + 2x + 4)

(x + 1) (square of X - x + 1) + (X-2) (square of X + 2x + 4)
=(x+1)(x²-x+1)+(x-2)(x²+2x+4)
=x³+1³+x³-2³
=2x³-7
This is the application of cubic sum and cubic difference

The symmetry axis of F (x) = x-bx + C image is x = 1, and f (0) = 3. Try to compare the size of F (x power of B) and f (x power of C)

The symmetry axis of F (x) = x-bx + C image is x = 1, and f (0) = 3,
∴-（-b)/2=1,c=3
B = 2, C = 3
When x > 0, the x power of B = 2 is greater than 1, and the x power of C = 3 is greater than 1
And the power of C is greater than that of B
Ψ f (x power of B)

Fractional addition and subtraction A / (a-b) + B ^ 2 / a (B-A)
（1）a/(a-b)+b^2/a(b-a)
（2）1/(m^2-m)+(m-5)/2m^2-2

(1) The original formula is a / (a-b) - B ^ 2 / a (a-b)
= a ^ 2 / a (a-b) - B ^ 2 / a (a-b) (general)
=(a^2-b^2)/a(a-b)
=(a + b) (a-b) / a (a-b) (molecular square difference)
=(a + b) / a (approximate)
＝1+b/a
(2) The original formula is 2 (M + 1) / 2m (m ^ 2-1) + m (m-5) / 2m (m ^ 2-1)
＝（m^2-3m+2）/2m(m^2-1)
=(m-1) (m-2) / 2m (M + 1) (m-1) (factoring the numerator and denominator separately)
=(m-2)/2m(m+1)

Y = x + 1 / (x + 1)

F '(x) = 1-1 / (x + 1) ^ 2, when x = 0 or - 2, it has extremum, when it is greater than 0, it increases, when it is less than - 2, it increases, X is not equal to - 1 -Decreasing from 2 to - 1, decreasing from - 1 to 0 (the image is discontinuous), the image is two hooks centered on (- 1,1) So the range (negative infinity, 1) U (1, positive infinity)

Math problems and answers in Volume 2 of grade 5

1) 2.9 × 0.5 = answer: 1.45 (2) 5.9 × 0.2 = answer: 1.18 (3) 3.6 × 7 = answer: 25.2 (4) 4.3 × 0.3 = answer: 1.29 (5) 5.9 × 9 = answer: 53.1 (6) 9.4 × 9 = answer: 84.6 (7) 7.5 × 6 = answer: 45 (8) 1.3

The solutions of the system of equations x = 6-2yx-y = 9-3a of X and y are opposite to each other

∵ the solutions of the equations {x = 6-2yx-y = 9-3a} about X and y are opposite to each other, ∵ x + y = 0 ∵ x + 2Y = 6 ∵ y = 6, ∵ x = - 6, ∵ X-Y = - 6-6 = - 12 = 9-3a, a = 7

Put 1 ~ 9 in the nine brackets of the following formula to make the equation hold
( )( )( )/(）（）＝（）（）/（）＝5568
Wrong, wrong, is () / () = () / () = 5568

(1)(5)(6)/(3)(9)=(2)(8)/(7)=(4)
(6)(5)(1)/(9)(3)=(2)(8)/(4)=(7)
(6)(5)(8)/(9)(4)=(2)(1)/(3)=(7)

If the focus of the hyperbola is on the y-axis, the length of the real axis is 6, and the asymptote equation is y = plus or minus 3 / 2x, the standard equation of the hyperbola is obtained

Since the focus of hyperbola is on the y-axis, the equation of hyperbola is Y & sup2; / A & sup2; - X & sup2; / B & sup2; = 1
Its asymptote equation is y = ± ax / b
It is known that 2A = 6, a / b = 3 / 2,
So a = 3, B = 2
The standard equation of hyperbola is Y & sup2 / 9 - X & sup2 / 4 = 1

A bookshelf has two layers, the upper and the lower, with a total of 128 books. The ratio of books on the upper and the lower layers is 5:3. How many more books are there on the upper layer than on the lower layer?

128 × (55 + 3-35 + 3) = 128 × (58-38) = 128 × 28 = 32 (Books) a: there are 32 more books in the upper class than in the lower class

How to judge the quadratic function a, B, C greater than or less than 0
A I know it's according to the direction of the opening
How to judge B and C?

C is the intersection of the function and the Y axis. The intersection is above the X axis, C is greater than 0; below, C is less than 0; at the origin, C = 0
B, it is related to the position of the axis of symmetry and the direction of the opening
If the opening is upward, a > 0, the axis of symmetry is on the left side of y-axis, b > 0; if the axis of symmetry is on the right side of y-axis, b > 0