A is the point of negative one on the number axis. Move a to the left two unit lengths along the number axis to reach B, then the number represented by B is

A is the point of negative one on the number axis. Move a to the left two unit lengths along the number axis to reach B, then the number represented by B is

-3

It is known that the area of the sector is 48 square centimeters. If the radius of the sector is reduced to half of the original, and the central angle of the circle remains unchanged, what is the area of the sector after reduction

If the radius is reduced by half, the arc length will be reduced by half, and the area s = L * r / 2 will be reduced to 1 / 2 * 1 / 2 = 1 / 4, that is, the reduced area will be 12 square centimeters

If the radius of the sector is reduced to 1 / 3 of the original and the central angle of the circle is expanded to 3 times of the original, how much is the area of the sector reduced?

I hope my answer is helpful to your study
The radius is increased by 3 times and the area is increased by 9 times;
The center angle is reduced to 1 / 3 of the original and the area is 1 / 3 of the original;

The first three of the four numbers are equal difference, and then the third is equal ratio. The first and fourth and the 16th. The ground 2 and the ground 3 add up to 12 to find the four numbers

According to the meaning of the title, the four numbers can be set as follows:
a,a+b,a+2b,(a+2b)^/(a+b)
a+(a+2b)^/(a+b)=16
a+b+a+2b=12
=>A = 0, B = 4 or a = 5, B = - 6
So these four numbers are 0, 4, 8, 16
Or 15, 9, 3, 1

There are four numbers. The first three numbers are equal difference, and the last three numbers are equal ratio. The first and fourth sum is 16, and the second and third sum is 12

Let four numbers be a, B, C and D
a+d=16
b+c=12
2b=a+c
c^2=bd
Then C = 12-b
a=3b-12
d=28-3b
We get (12-B) ^ 2 = B (28-3b)
We get B ^ 2-13b + 36 = 0
B = 4 or B = 9
(1) When B = 4
a=0
b=4
c=8
d=16
(2) When B = 9
a=15
b=9
c=3
d=1
dear!