How to calculate 125 * (40 + 8) * 25 skillfully? It must be skillful, not dead!

How to calculate 125 * (40 + 8) * 25 skillfully? It must be skillful, not dead!

125*(40+8)*25
=125*40*25+125*8*25
=125*1000+1000*25
=1000*（125+25）
=150000

125*(40-8)*25

125*(40-8)*25
=125x32x25
=125x8x4x25
=（125x8）x（4x25）
=1000x100
=100000

（1）x÷x＝x x＝ （2）x2＝2x x＝ （3
（1）x÷x＝x x＝
（2）x2＝2x x＝
（3）x＝x－x x＝

1÷1=1
Square of 2 = 2x2
0=0-0

If the value of fraction 2 (x-3) / x2 + 3 is 0, then the value of 2x / x2-1 △ 2x / 1-x is 0_______ .

∵2(x-3)/﹙x²+3﹚=0,
∴x=3
∴2x/﹙x²-1﹚÷2x/﹙1-x﹚
=﹛2x/﹙x²-1﹚﹜×﹛﹙1-x﹚/2x﹜
=﹙1-x﹚／﹛﹙x-1﹚﹙x+1﹚﹜
=﹣1/﹙x+1﹚
=﹣1/4

Is it right or wrong to make the value of fraction (x2-2x-2) / (X-2) be an integer?

(x²-2x-2)/(x-2)
=[x(x-2)-2]/(x-2)
=x(x-2)/(x-2)-2/(x-2)
=x-2/(x-2)
Is an integer, then X-2 is a divisor of 2
So X-2 = 1, - 1,2, - 2
So there are four
So right

x. If y is a real number and y = 2xx2 + X + 1, then the maximum value of Y is______

Therefore, y = 2xx2 + X + 1 can be transformed into YX2 + (Y-2) x + y = 0, which can be regarded as a quadratic equation of one variable with respect to x, ∵ x is a real number, ∵ x ≥ 0, that is, ∵ x = (Y-2) 2-4y2 = - (3y2 + 4y-4) = - (3y2) (y + 2) ≥ 0, ∵ (3y2) (y + 2) = - (3y2 + 4y-4) = (3y2) (y + 2) ≥ 0, ∵ (3y2) (y + 2) ≥ 0

The square of x plus 2x equals 15. The solution to this problem is that x equals 3, but how do you work it out?
Can play a comprehensive bonus!

x^2+2x=15
(x+1)^2=16
x+1=±4
X = 3 or - 5

(x + 2) (x2-2x + 4) + (x-1) (x2 + X + 1), where x = - two thirds

Original formula = X3 + 8 + x3-1
=2x3+7
=-16/27+7
=173/7

Simplification [2x / (x2-4) - 1 / (X-2)] · (x + 2) / (x-1)

[2x/(x2-4)-1/(x-2)]·(x+2)/(x-1)
=[2x/(x+2)(x-2)-1/(x-2)]*(x+2)/(x-1)
=(2x-x-2)/(x+2)(x-2)*(x+2)/(x-1)
=1/(x+2)*(x+2)/(x-1)
=1/(x-1)

x(2x-1)2-4(x-3)(x2+3x+9)-(9+2x)(9-2x)=0

x(2x-1)^2 -4(x-3)(x^2 +3x+9)-(2x+9)(9-2x)=0
x(4x^2 -4x+1)-(x^2 +3x+9)(4x-12)-(81-4x^2)=0
4x^3 -4x^2 +x-(4x^3 -12x^2 +12x^2 -36x+36x-108)-81+4x^2=0
4x^3 -4x^2 +x-(4x^3 -108)-9+4x^2=0
(4x^3 -4x^3)-(4x^2 -4x^2)+x+108-81=0
It is reduced to x = - 27
So the solution of the equation is x = - 27