Factorization - the third power of a, the third power of B + the third power of a, the third power of B - AB,

Factorization - the third power of a, the third power of B + the third power of a, the third power of B - AB,

-a³b³+a²b²-ab
=-ab(a²b²-ab+1)

It is known that a + B = 6, ab = 7. Find the quadratic power of a, the quadratic power of B + AB, and use the factorization of polynomials,

The original formula is ab (a + b) = 7 × 6 = 42

The sixth power of a + the third power of 7 A - 8 factorization result?

Analysis: Factorization by cross multiplication a ^ 6 + 7a ^ 3-8 = (a ^ 3 + 8) (a ^ 3-1) [pay attention to continue factorization by cubic sum and difference formula] = (a + 2) (a ^ 2-2a + 4) (A-1) (a ^ 2 + A + 1)

Using Ohm's law to measure the resistance of a small bulb, why can't we find the average value?

Because the resistance changes
In the experiment, the average value is often used to reduce the error
However, the resistance of the bulb is related to the temperature. When the temperature changes, the resistance also changes. It is no longer the same physical quantity. It is meaningless to average different physical quantities

3x（a-b）-2y（b-a）
a^2（y-3）+（3-y）
x^2（x-y)-(x-y)
4xy-4x^2y-y
(3a+2)^2-(a-6）^2
x^4-8x^2+16

3x（a-b）+2y（a-b）=(3x+2y)(a-b)
a^2（y-3）+（3-y）=a^2（y-3）-（y-3)=(a^2-1)(y-3)
x^2（x-y)-(x-y)=(x^2-1)(x-y)
4xy-4x^2y-y=y(4x-4x^2-1)=-y(4x^2-4x+1)=-y(2x-1)^2
(3a+2)^2-(a-6）^2=(3a+2+a-6)(3a+2-a+6)=(4a-4)(2a+8)=8(a-1)(a+4)
x^4-8x^2+16=(x^2-4)^2=(x+2)^2(x-2)^2

On May 1, 2012, Aunt Wang deposited 40000 yuan into the bank for two years at an annual interest rate of 4.4%. After the maturity, how much can Aunt Wang withdraw?

Interest: 40000 * 4.4% * 2 = 3520 yuan
Principal and interest: 40000 3520 = 43520 yuan

Mathematics problem master enters!
A manuscript, a single type needs 12 hours to complete, B single type 8 hours to complete
How many hours can we complete the task?
For processing a batch of parts, workshop a will do it alone for 4 hours, workshop B will do it alone for 6 hours, and how many hours will the two workshops cooperate?
It takes three hours for a car to go from place a to place B, and five hours for a truck to go from place B to place A. how many hours will the two cars meet each other?

1 / (1 / 12 + 1 / 8) = 4.8, Party A and Party B cooperate, 4.8 can complete the task
1 / (1 / 4 + 1 / 6) = 2.4 two workshop cooperation 2.4 hours to complete
1 / (1 / 3 + 1 / 5) = 15 / 8 the two trains leave each other at the same time and meet in 15 / 8 hours

A mathematical problem of formula method~~~
The square of the title 3x - 5x = 4~~~~~~~~

3x＾2-5x-4＝0
X = [- B + or B ＾ 2-4ac under - radical] / 2A
a＝3,b＝-5,c＝-4
Just calculate it

The following statements are correct: 1. The greater the frequency, the greater the frequency. 2. The sum of all frequencies is equal to 1.3. Frequency represents the number of occurrences of each object. 4. Frequency must be a positive number. OK,

1. Wrong. Because: frequency is the number of events, frequency is n / M (n is the number of events, M is the total number of experiments)
2. Yes
3. Frequency is the number of times an event occurs
4. Wrong, the frequency may be 0. For example, in the experiment of coin tossing, if 10 experiments are done, and 10 experiments are positive, the frequency of negative upward is 0

How to simplify the operation of 168 * 105

168*105
=168*(100+5)
=168*100+168*5
=16800+840
=17640