Given the absolute value M-1 = 2, try to solve the equation MX (x-1) + 3 = (2 + x) (2-x) about X

Given the absolute value M-1 = 2, try to solve the equation MX (x-1) + 3 = (2 + x) (2-x) about X

M-1 = 2 or M-1 = - 2, so m = 3 or - 1
-1 can be substituted into the equation to calculate x = 1
3 into the equation to calculate no real root

We know that for the equation of XY, the square of x plus the square of Y

Given the equation of X, y, X & # 178; + Y & # 178; - y + M = 0, if the circle C intersects the straight line x + 2y-4 = 0, m and N, and Mn = √ (4 / 5), find the value of M?
x^2+y^2-y+m=0
x+2y-4=0 x=4-2y
Substituting into circle: 16-16y + 4Y ^ 2 + y ^ 2-y + M = 0.5y ^ 2-17y + 16 + M = 0
M(x1,y1) N(x2,y2)
x1=4-2y1
x2=4-2y2
y1+y2=17/5
y1y2=(16+m)/5
Square of distance between two points = (x2-x1) ^ 2 + (y2-y1) ^ 2 = 4 / 5
(2y1-2y2)^2+(y2-y1)^2=4/5
(y2-y1)^2=4/25=(y1+y2)^2-4y1y2=289/25-(64+4m)/5
64+4m=285/5=57
m=-7/4

If the retail price of a commodity after two price cuts is 81% of that before the price cut, then the average price cut is ()
A. 10%B. 19%C. 9.5%D. 20%

Suppose that the average price reduction is X. according to the meaning of the problem, we get (1-x) 2 = 81%, and the solution is x = 0.1 or 1.9x = 1.9, which is not in line with the meaning of the problem, and we omit the average price reduction by 10%

The original price of a computer is 6000 yuan. In order to promote new products, the price is reduced by 10% first, and then increased by 10% after a period of time. How much is the current price of this computer?

6000×（1-10%）（1+10%）
=6000×0.99
=5940 yuan

Square of a-4ab + square of 4b-1

An algebra problem in the first grade of junior high school
Given that x satisfies (X-5) ^ 2 + (6-x) ^ 2 = 4, then (X-5) times (6-x) is equal to
The process should be detailed

Equal to - 1.5
(x-5)^2+(6-x)^2=x^2-10x+25+36-12x+x^2=2x^2-22x+61=4
Namely: x ^ 2-11x = (4-61) / 2 = - 28.5
Then: (X-5) (6-x) = 6x-x ^ 2-30 + 5x = - x ^ 2 + 11x-30 = 28.5-30 = - 1.5

How much is the profit rate of a commodity with a cost of 60 yuan and now sold at 80 yuan?

Profit margin includes sales profit margin and cost profit margin, sales profit margin = (selling price cost) / selling price, cost profit margin = (selling price cost) / cost
Profit rate is cost profit rate. It is equal to the ratio of profit to cost
Profit rate = (80-60) / 60 = 33.33%

One or two digits, and the sum of ten digits and one digit is 11. If the two digits are exchanged, the two digits obtained are 63 larger than the original number?

Let ten digits be x and one digit be y x + y = 11, 10Y + X - (10x + y) = 63
X=2 Y=9
It's 29

1、 Fill in the blanks
1. Given M-N = - 2 / 3, then 2 + M-N = 4 / 3, 7-3m + 3N=______
2. Given Mn-N = 15, m-mn = 16, then M-N=_________ ,-2mn+m+n=___________
3. If the square of (a + b) + |2b-1 | = 0, then ab - [2ab-3 (AB-1)]=_________
2、 Calculation problem (to process, the more detailed the better. Use the multiplication formula to calculate)
15 and 2 / 3 times (- 14 and 1 / 3)

The answer to question 3.4 upstairs is wrong
One
The answer to question 1 is 9
The answers to question 2 are 31 and 1
Three questions are - 7 / 2
2
The original formula = - (15 + 2 / 3) (15-2 / 3) = - (the square of 15-2 / 3) = - (225-4 / 9) = - 224 and 5 / 9
Note: 15 and 2 / 3 can be expressed as 15 + 2 / 3, 14 and 1 / 3 can be expressed as 15-2 / 3

As shown in the figure, it is known that the quadrilateral ABCD is a square, the diagonal AC and BD intersect at O, the quadrilateral aefc is a diamond, eh ⊥ AC, and the perpendicular foot is h. verification: eh = 12fc

It is proved that in square ABCD, AC ⊥ BD, AC = BD, OB = 12bd = 12ac, and ∵ quadrilateral aefc is rhombus, ∵ AC = CF, AC ∥ EF, ∵ eh ⊥ AC, ∵ DBC = ∵ abd = ∵ CBF = 45 °, ∵ boh = ∵ ohe = ∵ OBE = 90 °, ∵ quadrilateral beho is rectangle, ∵ eh = ob, ∵ eh = 12ac = 12CF