(3x+9)(6x+8) (3x+7y)(3x-7y) (1/3a^2b^2)(-15a^2b^2) (3mn+1)(3mn-1)-8m^2n^2 (x+2)^2-(x+1)(x-1) (x+y+z)(x+y-z) (1) (3x + 9) (6x + 8) (2) (3x + 7Y) (3x-7y) (3) (1 / 3A ^ 2B ^ 2) (- 15A ^ 2B ^ 2) (4) (3MN + 1) (3mn-1) - 8m ^ 2n ^ 2 (5) (x + 2) ^ 2 - (x + 1) (x-1) (6) (x + y + Z) (x + Y-Z) the above is a little unclear, that's right

(3x+9)(6x+8) (3x+7y)(3x-7y) (1/3a^2b^2)(-15a^2b^2) (3mn+1)(3mn-1)-8m^2n^2 (x+2)^2-(x+1)(x-1) (x+y+z)(x+y-z) (1) (3x + 9) (6x + 8) (2) (3x + 7Y) (3x-7y) (3) (1 / 3A ^ 2B ^ 2) (- 15A ^ 2B ^ 2) (4) (3MN + 1) (3mn-1) - 8m ^ 2n ^ 2 (5) (x + 2) ^ 2 - (x + 1) (x-1) (6) (x + y + Z) (x + Y-Z) the above is a little unclear, that's right

(1)(3x+9)(6x+8)=18x^2+24x+54x+72=18x^2+78x+72(2)(3x+7y)(3x-7y) =9x^2-49y^2(3) (1/3a^2b^2)(-15a^2b^2) =(-15a^2b^2)/(3a^2b^2)=-15/3=-5(4)(3mn+1)(3mn-1)-8m^2n^2 =9m^2n^2-1-8m^2n^2=m^2n^2-1(5) (x+2)^2-(x+...

3x plus one half equals twelve

3x+1/2=12
So 3x = 12-1 / 2 = 23 / 2
So x = 23 / 6

First remove the brackets, and then merge the similar items (x-1) - (2x + 1)

（x-1）-（2x+1）
=x-1-2x-1
=-x-2

Given that the solution set of inequality 2 (M-X) + 1 ＞ 3x-2 is x ＜ 32, then the value of M is ⊙___ ．

The solution set of inequality 2 (M-X) + 1 ＞ 3x-2 is x ＜ 32, ∧ 2m + 35 = 32, ∧ M = 94

Is there a mobile calculator that can calculate results or processes everywhere

You can check that there is a mobile scientific calculator, which is very useful

A small ball begins to roll forward at the speed of 5 m / s, and decelerates evenly. After rolling for 10 m, the ball stops. (1) how long does the ball roll? (2) How much does the average ball speed decrease per second? (3) How long does it take for the ball to roll to 5M?

(1) According to the meaning of the question, the average rolling speed of the ball is the average value of the maximum speed and the minimum speed, that is, 5 + 02 = 2.5 (M / s), and the time from rolling to stopping is 10 △ 2.5 = 4 (s); (2) the decrease value of the average speed per second from rolling to stopping is: the speed change △ the time of the ball moving speed change, that is, 5 △ 4 = 1.25 (M / s), and (3) the time for the ball rolling to 5M The time is XS. From (2), we can see that the average speed reduction from rolling to stopping is 1.25 (M / s). The time taken for the ball to roll to 5M is XS, and the original speed is 5m / s. at this time, the ball rolling speed is: (5-1.25x) m / s, and the average speed in this period is 5 + (5 − 1.25x) 2m / s, that is, (5 − 58x) m / s. from speed × time = distance, (5 − 58x) x = 5, and x2-8 X + 8 = 0, x = 4 ± 22. That is, X1 = 4 + 22 ≈ 6.8, X2 = 4-22 ≈ 1.2. A: it took about 1.2 seconds for the ball to roll to 5 meters

The sum of binomial coefficients With Sum of coefficients
1… How to distinguish: the sum of binomial coefficients and the sum of various coefficients
2… Their solution! Macro point of

You can see, for example
(1+2x)^3
=1×1^3+3×(1²×(2x))+3×(1×(2x)^2)+1×(2x)^3
The binomial coefficients of each item are: 1,3,3,1
=1+6x+12x^2+8x^3
The coefficients of each item are 1,6,12,8 respectively
The binomial system is certain, even if the terms in it are different, the binomial coefficients are the same
The coefficients are uncertain and have relations with the coefficients of the expanded items~~

It is known that a + B = 3 AB = 1 / 2 (a ^ 2 + B ^)
It's B ^ 2

（A^2+B^2)/2=[(A^2+B^2)+2AB-2AB]/2=[(A+B)^2-2AB]/2=(9-4)/2=2.5

Square of (x + 1) - 25 = 0 square of (X-2) = (2x + 3) square of (X-2) (x-3) = 12 all quadratic equations of one variable are solved by factorization
Thank you

Square of (x + 1) - 25 = 0 (x + 1 + 5) (x-1 + 5) = 0 (x + 6) (x + 4) = 0x1 = - 6, square of x2 = - 4 (X-2) = square of (2x + 3) ^ 2 - (2x + 3) ^ 2 = 0 (X-2 + 2x + 3) (x-2-2x-3) = 0 (3x + 1) (- X-5) = 0x1 = - 1 / 3, X2 = - 5 (X-2) (x-3) = 12 x ^ 2-5x + 6 = 12x ^ 2-5x-6 = 12 (X-6) (...)

Solving equation x ^ 4-2x ^ 3-6x ^ 2 + 6x + 9 = 0

x^4-2x^3-6x^2+6x+9=(x-3)(x+1)(x^2-3)=0
x=3、-1、-√3、√3