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Guo Xu, I am silent for you, I have an exam today, hehe.

It will only be the 22nd this year and the 23rd next year.

If (2a) (3bc) 6657, then (abc) here (2a) is used to denote a two-digit number, not multiplication, and another is similar).

First of all, we can know that a and c are both odd numbers, otherwise the product of the two numbers cannot be odd numbers, secondly, a 1, otherwise a 3, (2a) (3bc) 23 300 6900

Thus, (3bc) 6657 21 317, i.e. b 1, c 7 then (3bc) 117

You won't find this on the Internet!! Do you have a topic?

y = 6x / (6 - x)

6x - 36 + 36) / (6 - x)= [6(x-6) +36 ]/ (6-x)= -6 + 36/(6-x)

To make y minimum, 36 (6-x) is minimal, then 36 (6-x) is minimum 1 when 6-x = 36.

ymin = -6 + 1 = -5

Simplify y=6x 6-x to -6(1+6 (x-6)), and require the minimum value of y to find the minimum value of x-6.

From the meaning 6-x>0 and x<0 can only get x<0, so the minimum value of y cannot be found.

So using y to represent x gives x=6y (6+y) and x and y are both negative integers, and the minimum value of 6+y>0 y is -5

55, -2 or 0

57. Isosceles right triangle.

58, the root of the second is number three.

59. X is greater than or equal to 1 and less than 3, 8, 10

Degree. Degree. 36 degrees.

66, root number five.

67, three-sevenths.

68. Sixteenths of a l. squared.

a+b) 70, three-sevenths.

71, four-fifteenth.

72、s=4n-4

76. Minimum: 130

Maximum: 738

78, ab79, circumference equal.

Give points.

With E as the midpoint, then the area of the triangle AEC = the area of the triangle CED, and the area of the triangle ABE = the area of the triangle BED.

By the triangle abc area = 1

Then the area of the triangle AEC + the area of the triangle ABE=, the area of the triangle EFB = so the area of the triangle AFC =

i.e. the area of the triangle bfc =

So the area of the triangle AEF: the area of the triangle BEF = the area of the triangle AFC: the area of the triangle BFC = :

That is, the area of the triangle AEF = 2 3 * (1 10) = 1 15

For the sake of convenience, let's set two unknowns:

Let s aef=x and s aec=s ced=y

1.According to, S bed = S bef + S aef = x +1 10 because the bottom edge is equal ae=ed, and the high edge is equal.

2.Then 2(x+1 10) +2y = 1 utilizes a total area of 1

3.According to fe ec = s aef s aec = x y

fe / ec = s▲bef / (s▲bed+s▲dec) = (1/10) / (x+1/10+y) ②

Synthesis, can be obtained: x=1 15 y=1 3

**And Shigeru, did my lesson!

Solution: S AEF + S BEF + S AEC=1 2 S AEF + S AEC=1 2-S BEF=1 2-1 10=2 5

i.e. s afc=2 5 so s bfc=3 5 s afc s bfc=af bf=2 3 again s aef s bef =af bf=2 3 i.e. s aef=s bef*2 3=1 15

It's that simple.

1.If both a and b represent rational numbers, and a+b = 0, then (c)a)a, and b are both 0

b) a, one of b is 0

c) A and b are inverses to each other.

d) A and b are reciprocal to each other.

2.If the GDP of a factory last year increased by 1% compared with the previous year, then the percentage of the previous year less than last year is (d)a)a%.

b)(1+a)%

c)(a+1)/(100a)

d)a/(100+a)