If the distance between the line L passing through point P (1,2) and two points a (2,3). B (4, - 5) is equal, then the equation of the line L is? There are four answers: a.4x + y-6 = 0, b.x + 4y-6 = 0, c.3x + 2y-7 or 4x + y-6 = 0, d.2x + 3y-7 = 0 or x + 4y-6 = 0

If the distance between the line L passing through point P (1,2) and two points a (2,3). B (4, - 5) is equal, then the equation of the line L is? There are four answers: a.4x + y-6 = 0, b.x + 4y-6 = 0, c.3x + 2y-7 or 4x + y-6 = 0, d.2x + 3y-7 = 0 or x + 4y-6 = 0

Let the line passing through point p be Y-2 = K (x-1), that is, K (x-1) - y + 2 = 0, the distance from point a to the line = | k-1 | / root sign (k ^ 2 + 1), the distance from point B to the line = | 3K + 7 | / root sign (k ^ 2 + 1) = | 3K + 7 | / root sign (k ^ 2 + 1) | k-1 | = | 3K + 7 | k = - 4 or - 3 / 2, the line is y = - 4x + 6 or 3x + 2y-7 = 0

Find the equation of line L passing through point (1,2) and equal to the distance between point a (2,3) and point B (4, - 5)

The slope of line AB is (- 5-3) / (4-2) = - 4
Because the distance between the line and points a (2,3) and B (4, - 5) is equal
So the line is perpendicular to ab
So the slope is k = 1 / 4
So the equation is Y-2 = (1 / 4) * (x-1)
That is x-4y + 7 = 0

Let Sn be the sum of the first n terms of the arithmetic sequence an, and the median terms of (1 / 3) S3 and (1 / 4) S4 are the median terms of (1 / 5) S5, (1 / 3) S3 and (1 / 4) S4
Let Sn be the sum of the first n terms of the arithmetic sequence an, and the middle term of the ratio of (1 / 3) S3 and (1 / 4) S4 is (1 / 5) S5, and the middle term of the difference of (1 / 3) S3 and (1 / 4) S4 is 1, then the general formula of the arithmetic sequence an is obtained

Let an = a1 + (n-1) d S3 = a1 + A2 + A3 (1 / 3) S3 = a1 + D
（1/4）S4=a1+(3\2)d
(1\5)S5=a1+2d
（1/3）S3+（1/4）S4=2a1+5\2d=2 （1/3）S3*（1/4）S4=(1\5)S5*(1\5)
The solution is A1 = 4-7, d = 12-35, so an = 12-35n + 8-35

The car runs at a constant speed of 36km / h, and now accelerates at an acceleration of 0.6m/s2. What is the speed after 10s?

36km / h = 10m / s. according to the speed time formula, the speed after 10s is v = V0 + at = 10 + 0.6 × 10m / S = 16m / s. answer: the speed after 10s is 16m / s

Xiaojun's walking distance is 14 more than Xiaohong's, but Xiaohong's walking time is 110 more than Xiaojun's______ ．

The distance ratio of Xiaojun and Xiaohong is: (1 + 14): 1 = 54:1 = 5:4; the time ratio of Xiaojun and Xiaohong is: 1: (1 + 110) = 1:1110 = 10:11; then the speed ratio of Xiaojun and Xiaohong is: (5 ﹣ 10): (4 ﹣ 11) = 510:411 = 11:8

1、 Multiple choice questions (30 × 2)
1. Most of the water absorbed by plants from soil (a)
A. Used for photosynthesis B. used for respiration C. used for transpiration D. stored in the body
2. Reasonable irrigation means (d)
A. More irrigation B. more irrigation before less irrigation
C. Irrigation from less to more D. timely and appropriate irrigation according to the needs of plants
3. The water squeezed out from vegetables mainly comes from (b)
A. Cytoplasm B. vacuole C. nucleus D. cell membrane
4. The main part of root absorbing water and inorganic salt is apical (d)
A. Root cap B. elongation zone C. meristem zone D. mature zone
5. The main transport channel of organic matter in plants is (b)
A. Vessel B. sieve tube C. phloem D. cambium
6. Cut off the stem of young plants, and the sap will seep from the cross section of the stem, which mainly comes from (c)
A. Sieve tube B. cambium C. vessel D. phloem
7. The main part of transpiration is ()
A. Young stem B. leaf C. petiole D. root
8. Compared with guard cells, epidermal cells of leaves did not contain ()
A. Cell wall B. large vacuole C. nucleus D. chloroplast
9. The stomata of terrestrial plants are mostly distributed in the lower epidermis
A. It can accelerate the transpiration of water. B. It can reduce the loss of water
C. It is beneficial to the absorption of carbon dioxide and the escape of oxygen from the leaves
10. When doing the experiment of "green leaves make starch under light", the correct order should be ()
① Alcohol decolorization, water washing, leaf selection and shading, dark treatment, iodine wine development and observation
A．④③①②⑤⑥ B．③④①⑤②⑥ C．④③⑤①②⑥ D．③④①⑤⑥②
11. In the experiment of "green leaves make starch under light", Geranium should be put in the dark for a day and a night
（ ）
A. The starch in the leaves is consumed
B. The starch in leaves is stored in chloroplast
C. Stop photosynthesis and store starch in mesophyll cells
D. Reserve nutrients for photosynthesis
12. The site of photosynthesis in plants is ()
A. Mitochondria B. chloroplast C. nucleus D. cell membrane
13. The photosynthesis of green plants is ()
A. Synthesize organics and release energy B. synthesize organics and store energy
C. Decompose organic matter and release energy D. decompose organic matter and store energy
14. After respiration decomposes organic matter, the substance produced is ()
A. Inorganic salts and water B. water and starch
C. Oxygen and starch D. decompose organic matter and store energy
15. The place where plants breathe is ()
A. Mesophyll cells B. epidermal cells C. guard cells D. all living cells

CDBDB
CBDBC
ABB?D
The most standard answer to question 14 is: carbon dioxide + water, but no
The other should be c

The number corresponding to point a on the number axis is - 5. Point B is on the right side of point A. electronic ant a and B move to the left at the speed of 2 units per second and 1 unit per second respectively at point B. 1. If electronic ant C moves to point C after 5 seconds, calculate the number represented by point C. 2. They start at the same time. If C meets B one second after meeting a, calculate the number represented by point B. 3, Is there a value of T, which is the distance from C to B and twice the distance from C to a? If so, find out the value of T; if not, explain the reason

The number corresponding to point a on the number axis is - 5. Point B is on the right side of point A. electronic ant a and B respectively move to the left at the speed of 2 units per second and 1 unit per second at point B
The number corresponding to point a on the number axis is - 5. Point B is on the right side of point A. electronic ant a and B move to the left at the speed of 2 units per second and 1 unit per second respectively at point B. 1. If electronic ant C moves to point C after 5 seconds, calculate the number represented by point C. 2. They start at the same time. If C meets B one second after meeting a, calculate the number represented by point B. 3, Is there a value of T, which is the distance from C to B and twice the distance from C to a? If so, find out the value of T; if not, explain the reason
2. They set out at the same time. If C meets B one second after meeting a, find the number represented by B. answer: a - (- 5), ---- (b) a - (- 5), ---- (b) (A and b) C meets a one second after meeting a, that is, the time is determined, the mass is unchanged, the distance is unchanged, the function is unchanged, and the change is the distance. Then, they start at the same time. It shows that the starting is the same, the speed is the same, and the space is different. Solid, 5-1 = 4, we get: a - (- 5), ---- (b) a - (- 5), ---- (b) a - (- 5), -----(B) (b) - 4
3. Under the condition of (2), let them start at the same time in T seconds. Is there a value of T, that is, the distance between C and B is twice the distance between C and a? Wrong, why? A: T seconds assumes that there is no time, that is to say, they do not change back to Newton

A suit of clothes costs 260 yuan, of which the price of trousers is 58% of that of the coat. How much are the coat and trousers?

260 × 58 + 5 = 260 × 513, = 100 (yuan). 260-100 = 160 (yuan). Answer: the price of coat is 160 yuan; the price of trousers is 100 yuan

If the root of loga is less than 1, then the value range of real number a is I

When a > 1, the root number of loga is 2, the root number of loga is 2;
(2) When 0

Fill in the appropriate number in the horizontal line: ⊙ ⊙ 1.2 cubic decimeter =___ L =___ Ml; ⊙ 7504g =___ Kg; ⊙ 6 cubic meters, 40 cubic decimeters___ Cubic meter

2 cubic decimeter = 1.2 liter = 1200 ml; ⊙ 7504g = 7.504 kg; ⊙ 6 cubic meter 40 cubic decimeter = 6.04 cubic meter; so the answer is: 1.21200, 7.504, 6.04