Math questions, please answer, math questions, please answer

Solution: The area of the figure enclosed by Xiaohong, Xiaolan and Xiaobai is S1, S2 and S3 respectively. It depends on the title.

s1=4*π（1/2π）²=1/π

s2=2*π(2/2π)²=2/π

s3=π*(4/2π)²=4/π

So the ratio of the area of the figure they enclose is 1:2:4

The total area of the figure surrounded by the three people is Xiaohong: pie * (1 2 pies) square * 4 = 1 pie.

Xiaolan: pie * (2 2 pies) square * 2 = 2 pies.

Xiaobai: pie * (4 2 pies) square * 1 = 4 pies.

Since the letters and numbers cannot be written, this is good expediency, I hope forgive me) The ratio of the total area of the figure surrounded by the three people is Xiaohong: Xiaolan: Xiaobai = 1 faction: 2 faction: 4 faction = 1:2:4

Radius r perimeter c area s

From c = 2 r, r = c (2) from s = *r*r, s = (c*c) (4) red s = 1

Xiaolan s = 2

White s = 4

The area ratio is 1:2:4

Circle area = r = (1 4) circumference

Xiaohong's circle area = 4 (1 4) 1 =1 Xiaolan's circle area = 2 (1 4) 2 =2 Xiaobai's circle area = (1 4) 4 =4 The area ratio is Xiaohong: Xiaolan: Xiaobai = 1:2:4

The circle of small red: the circumference of 1=2 r gives r=1 (2), then the area s= r 2*4=1

The circle of Xiaolan: the circumference of 2=2 r gets r=1 , then the area s= r 2*2=2

Xiaobai's circle: the circumference is 4=2 r to get r=2, then the area is s= r 2*2=8

then their figure area ratio is 1:2:8

The ratio of area is 1:1:1

Let the rope be long x, then there is 2 r=x; i.e. r=x(2) s= r*r=x(4).

The area brought in is equal to 1

The radius of the first circle is 1 2 factions, and the total area is 4 * factions (1 2 factions) = 1 faction, the second total area is 2 factions, and the third total area is 4 factions. So the ratio is 1 to 2 to 4

1. The answer is 3 The same molecular ratio has no effect.

2. The next one is ten out of six.

Starting with the first numerator is 6, the second denominator is 7, the third numerator is 8, and the fourth denominator is 9, from which the fifth numerator 10 can be derived

The first denominator starts with 2, the second numerator is 4, the third denominator is the same as 4, and the fourth numerator starts with 6

From this, we can see that the fifth denominator should also be 6

So the result is 10 out of 6.

If a:b=3, then half of a:half of b = (3) of half. Six, seventh.

Four, quarters.

Eight, six-ninths [tenths of sixths].

The volume is the maximum volume that can hold water in the glass tank, and the inside is also the thickness of the cuboid minus twice the original length, and the thickness on both sides of the length is the thickness of the original width minus twice the thickness.

The height is the original height minus double the thickness, because there is no cover on it, only the thickness of the ground needs to be subtracted, and the volume is (cubic centimeters.

(cubic centimeters.)

The outer and inner volumes can be found with a*b*c=v.

Then subtract to the next level.

Without a cover, the length and width must be subtracted from the glass thickness twice, so the volume of the fish tank is equal to 60 * 30 * 40 = 72,000 cubic centimeters.

It can be seen from the question.

a+b=ck

a+c=bk, subtract the two formulas to obtain: b-c=(c-b)k, k=-1

a + b = ck;

a + c = bk;

b + c = ak;

Subtract any two equations, such as the last two, to get.

a - b = (b - a)k

k = -1;

k =2

If a=b=c, b-c=(c-b)k, then k can be any value instead of -1

Of course it's -1, because a+b+c=0 can't be a divisor, so it won't be 2

Have eaten for 12 days, eating an average of 3, 4 tons per day.

In 12 days, I ate a total of 12*3 4=9 tons, and the remaining 25-9=16 tons.

The rest eats 4 5 tons a day, and you can also eat 16 (4 5) = 20 days.

12*3/4=9

Tons 25-9 = 16

T 16 divided by 4 5 = 20 days.

So you can still eat it for twenty days.

The rest of the flour: 25-12*3 4=16

Eat for a few days: 16 (4 5) = 20 days.

Any real number has a cube root.

The square root is 2-x 0

x 2 denominator (2x+1)≠0

2x+1≠0

x≠-1/2

So x2 and x≠-1 2

Examples|-4|5 Then 5 should be greater than or equal to 4 and less than or equal to 4