The sum of ABC is 65, a is 5 bigger than B, B is 9 bigger than C, what are ABC?

The sum of ABC is 65, a is 5 bigger than B, B is 9 bigger than C, what are ABC?

C＝（65-9-9-5）/3＝14
B=C+9=14+9=23
A=B+5=23+5=28

Calculation: (a-b) ^ 7 / (B-A) ^ 5

(a-b)^7/(b-a)^5
=-(a-b)^7/(a-b)^5
=-(a-b)²
=-a²+2ab-b²

(a-b) ^ 2 / (a + b) ^ 2 / (B-A) ^ 3 / (B + a) ^ 3

Original formula = - (a-b) ^ 2 / (a-b) ^ 3 * (a + b) ^ 2 * (a + b) ^ 3
=1/(b-a)(a+b)^5

Calculation (a ^ 2-B ^ 2) / (a-b)

(a^2-b^2)÷(a-b)
=(a+b)(a-b)÷(a-b)
=a+b

Starting from 2, continuous even numbers are added, the number of addends is n, and the sum is s, and the value of 102 + 104 + 106 +. + 2012 is calculated

Because of the continuous even number in, from 102 to 2012, we can calculate the common even number: n = (2012-100) / 2 = 956
So: S = (a1 + an) × n / 2 = (102 + 2012) × 956 / 2 = 1009536

Starting from 2, continuous even numbers are added. The sum of them is shown in the following table. The number of addends is n and the sum is s
The number of addends n s
1 2 = 1×2
2 2＋4 = 6 = 2×3
3 2＋4＋6 = 12 = 3×4
4 2＋4＋6＋8 = 20 = 4×5
5 2＋4＋6＋8＋10 = 30 = 5×6
..
(1) Try to calculate when 8 even numbers are added, and S = ()
(2) When n even numbers are added, the relation between S and N is ()
(3) The value of 2 + 4 + 6... + 2004 is ()
If I have an answer, I can go to prepare the rope!

（1）72
（2）s=n*(n+1)
(3)1005006

Starting from 2, continuous even numbers are added, and their sum is shown in the following table: the sum of addends (s) 12 = 1 × 22 + 4 + 6 = 2 * 3 32 + 4 + 6 = 12 = 3 * 4
Starting from 2, continuous even numbers are added, and their sum is shown in the following table:
Sum of addends (s)
1 2=1×2
2 2+4+6=2*3
3 2+4+6=12=3*4
4 2+4+6+8=20=4*5
5 2+4+6+8+10=30=5*6
Calculate 202 + 204 + 206 + according to the above rule +300

First of all, mention 200, and convert your current expression to: 200 * 50 + (2 + 4 + 6 +... + 100). You can use a mathematical formula in the brackets. I forgot the specific one. I haven't used mathematics for many years. Go to the book and set up a formula. OK, arithmetic sequence
But according to the above, it is 50 * 51

The sum of three even numbers is 60. What is the number in the middle

Let an even number in the middle be x, the smallest be X-2, and the largest be x + 2,
（x-2）+x+（x+2）=60
x=20
A: the even number in the middle is 20

The sum of three consecutive even numbers is 144, and the middle number is X. can you solve these three numbers by using the method of equations?

Let the number in the middle be x, then the even number smaller than it is X-2; the even number larger than it is x + 2, so that x + (X-2) + (x + 2) = 144, so that x = 48, so that the three numbers are 464850

3. The sum of three consecutive even numbers is 10 greater than the largest one, which means what are the three consecutive even numbers? What is their sum?

Let the middle number be x, 3x - (x + 2) = 10, and then solve the equation