Use the factorization method to solve the following equation (1 - √ 3) y ^ 2 = (1 + √ 3) y "√" stands for the root There is also a (x-1) (x + 3) - 2 (x + 3) ^ 2 + 3 (x-3) (x + 3) = 0 It's all factorization

Use the factorization method to solve the following equation (1 - √ 3) y ^ 2 = (1 + √ 3) y "√" stands for the root There is also a (x-1) (x + 3) - 2 (x + 3) ^ 2 + 3 (x-3) (x + 3) = 0 It's all factorization

(1-√3)y^2=(1+√3)y
=(1 + √ 3) y (Y-1) = 0, y = 0 or y = 1
(x-1)(x+3)-2(x+3)^2+3(x-3)(x+3)=0
(x+3)(x-1-2x-6+3x-9)=0
(x+3)(2x-15)=0
X = - 3 or x = 15 / 2

Factorization method to solve equation. X ^ 2 = 7x

x^2=7x
x^2-7x =0
X（X-7）=0
Then x = 0 or x = 7

X ^ 2 – 7x – 1 = 0 use factorization method to solve equation

x^2-7x-1=(x-7/2)^2-53/4=(x-7/2+v53/2)(x-7/2-v53/2)=0
——》x1=7/2-v53/2,
x2=7/2+v53/2.

What is the law of 2,3,5,7,10,13,17,21,26,31,37 and what is the number 2005

This problem is divided into odd and even items
Odd term: 2,5,10,17,26,37, the rule is n & sup2; + 1, for example, 37 = 6 & sup2; + 1
Even number terms: 3,7,13,21,31 are n x (n + 1) + 1, for example, 31 = 5 x 6 + 1
The 2005 number is an odd number item, and it has 1002 odd numbers and 1002 even numbers in front of it, so n = 1003, the answer = 1003 & sup2; + 1

(1) It ther are no examinatinos,we can have _____ at school.
A more happier B a more happier time C much happier D a much happier time
(2)Are you feeling____ ?
A much well B much better
(3)Jay Chou is a famous singer.He is popular_____ people.
A to B for C with Dabout
Why are there two different answers to the third question? Which one is it?

D
B
A

Rectangular trapezoid ABCD, ad parallel BC, ∠ a = 90 °, ab = 7, Da = 2, BC = 3, there is a point P on AB, so that P, a, D are the triangle of vertex
Similar to a triangle with vertices P, B and C, how many points P have and the length of PA

When ∠ DPC is right angle or ∠ APD = ∠ CPB, the two triangles are similar, let PA be X
When ∠ DPC is right angle, AD & sup2; + AP & sup2; = PD & sup2; Pb & sup2; + BC & sup2; = PC & sup2;
PD²＋PC²=CD²
Then (2 & sup2; + X & sup2;) + [(7-x) & sup2; + 3 & sup2;] = (7 & sup2; + 1 & sup2;) x = 1orx = 6
When ∠ APD = ∠ CPB, the tangent values of two corners are equal
AD/AP=BC/PB 2/x=3/(7-x) x=14/5

42÷[14－（50－39）] 2.25×4.8＋77.5×0.48

42÷[14－（50－39）]
=42÷（14-11）
=42÷3
=14
2.25×4.8＋77.5×0.48
=2.25×4.8+7.75×4.8
=（2.25+7.75）×4.8
=48

Weighted average or arithmetic average
Why is sometimes the weighted average price greater than the arithmetic average price and sometimes the weighted average price less than the arithmetic average price

First of all, you need to understand what right means. Literally, right is a weight. It is used to weigh objects horizontally. Therefore, the higher the weight of a certain number, the greater the proportion it occupies, and the more it affects the result
For example, if you score 80 in the midterm and 90 in the final exam, the average score of your two exams is 85
But we think the final exam is more important. It should account for 60% of the average score, and the mid-term exam should account for 40%. Then the weighted average of the two exams is 80 * 40% + 90 * 60% = 86, which is larger than the arithmetic average, because the score of weight is higher. If the mid-term exam accounts for 40% and the final exam accounts for 60%, then the weighted average is 80 * 60% + 90 * 40% = 84, which is smaller than the arithmetic average
In fact, the arithmetic mean is that each number has the same weight. For example, the above example is that the mid-term exam is as important as the final exam, each accounting for 50%, 80 * 50% + 90 * 50% = 85
Therefore, which of the weighted average and the arithmetical average is larger depends on the weight of the large number higher than the average (whether it is higher than 50%)

In Pingsi ABCD, be is vertical ad, BF is vertical CD, the perpendicular foot is e, F, the perpendicular center of triangle bef is h, if DG is vertical BC, the perpendicular foot is g, the proof is: BH = GF
Try to be clear and easy to understand

Make a picture according to the title
Since h is the vertical center of △ bef, eh ⊥ BF, FH ⊥ be (vertical foot is m)
∵DG⊥BC,BE⊥AD
AD‖BC
The quadrilateral debg is a rectangle
∴DG=BE——————————————————①
∵FM⊥BE,EH⊥BF
∴FM‖DE,EH‖CD
The quadrilateral EDHF is a parallelogram
∴DF=EH——————————————————②
∵AD‖BC,DG⊥BC,BE⊥AD
∴DG‖BE
FM be
∴FH⊥DG
∴

If a man-made satellite circulates around the earth at a uniform speed and its orbit radius is 13 times of that of the moon around the earth, the cycle of the satellite is about ()
A. 1-4 days B. 4-8 days C. 8-16 days D. 16-20 days

According to gmmr2 = MR (2 π T) 2, t = 4 π 2r3gm, then the period ratio of the satellite to the moon is t star, t month = 127 = 133. The period of the moon around the earth is about 27 days, then the period of the satellite is t star ﹥ 5.77 days