Sum of equal ratio sequence! How many positive integers less than 100 are multiples of 6 and sum them?

Sum of equal ratio sequence! How many positive integers less than 100 are multiples of 6 and sum them?

The multiple of 6 is 6N
6N
100/6=16…… Four
16
6，12，18…… 6N
S=6+12+…… +96=16*（6+96）/2=816
It's an arithmetic sequence
Multiple of 6:
6，12，...，96
number:
96 / 6 = 16
And:
（6+96)*16/2=816
Hello, landlord~~
100/6 = 16.6
Take the whole number to get 16
6+12+…… +96 ＝ 6(1+2+…… +16) = 6(17*8) = 816
The summation formula of equal difference and equal ratio is fast,
Equal difference: SN = (a1 + an) / 2 * n
Equal ratio: SN = A1 * (1-Q ^ n) / (1-Q) (when q is not equal to 1)
Sn=n*a1(q=1shi)
Equal difference equal ratio summation formula
Let {an} be an arithmetic sequence with the first term A1 and the tolerance D
Then the sum of the first n terms is
Sn=n(a1+an)/2
Or Sn = Na1 + n (n-1) d / 2
Let {an} be an equal ratio sequence, the first term A1, and the common ratio Q
Then when Q ≠ 1, the sum of the first n terms is
Sn=a(1-q^n)/（1-q)
Or Sn = (A1 anq) / (1-Q)
When q = 1, Sn = Na1
Division of the same base power
1. The correct number in the calculation of the following formulas is ()
1. 0 power of 10 / 1 power of 10 = 10
2. 10 to the power of - 4 * (2 * 7) = 10000
3. 0 power of (- 0.1) / - 3 power of (- 1 / 2) = 8
4. The fourth power of (- 10) / (- / 10) = - 1
If n is a positive integer, then the result of N + 1 power of (- 5) / N power of [5 * (- 5) is
Calculation: power 0 of 100, power - 1 of 10 = (), power 2009 of 2, power - 2008 of 2 = ()
]
1. The correct numbers in the calculation of the following formulas are (1)
1. 0 power of 10 / 1 power of 10 = 10
2. 10 to the power of - 4 * (2 * 7) = 10000
3. 0 power of (- 0.1) / - 3 power of (- 1 / 2) = 8
4. The fourth power of (- 10) / (- / 10) = - 1
If n is a positive integer, then the result of N + 1 power of (- 5) / N power of [5 * (- 5) is - 1
Calculation: power 0 of 100, power - 1 of 10 = (0.1), power 2009 of 2, power - 2008 of 2 = (2)
As shown in the figure, there are three squares on the straight line. The area of the square placed obliquely is 4. The area of the two squares placed upright is S1. S2, then S1 + S2 =?
Because they are all squares, it is not difficult to find out that the two triangles on the graph are congruent triangles, and the area of the inclined square is 4, so its side length is 2. If the side lengths of the other two squares are a and B, according to the Pythagorean theorem, then the square of a + the square of B = the square of 2, so S1 + S2 = 4
Mathematical calculation problem: calculate the following formula with the meaning of power
【1】 The fourth power of - 2 [2] (- 2 / 3) is the third power of [3] - the second power of 2 / 3
one point one six
2.（-8/27）
3.4/9
"The same base power division" formula related problems, please 3Q
Letter formula A ^ m △ a ^ n = a ^ M-N (a ≠ 0, m, n is a positive integer, and m ＞ n) 1. Why can't the base number a be equal to 0? 2. Why m ＞ n? If M = n, m ＜ n? 3. Can a in the formula be a number, a monomial or a polynomial?
If a = 0, then the nth power of a is also 0, because the divisor cannot be 0, then a cannot be 0. Because m > n is easy to calculate, I will learn M = n, m in the future
1: If a = 0, then the nth power of a = 0, then the divisor is equal to. And the divisor cannot be 0, so a cannot be 0. 2: M = n, then the formula = 1, if M
There are seven triangles on the line L at one time. It is known that the areas of the three triangles placed obliquely are 1, 2 and 3, and the areas of the triangles placed upright are S1, S2 and S3
It should be four, because according to the Pythagorean theorem, the square area on the hypotenuse is equal to the sum of the square areas of two right angle sides, so S1 plus S2 equals 1, S3 plus S4 equals 3, so = 1 + 3 = 4
emergency
How many cells can a certain cell divide from one to two every 15 minutes
One hour is 60 minutes, or four 15 minutes
So four hours is 16 15 minutes
So it split 16 times
So it splits into 2 to the 16th power, that is 65536
4*60/15=16
2^(16-1)=32768
2 to the 16th power
2^(4·60/15) = 2^16 = 65536
4 * 60 / 15 = 16, split sequence has 1, 2, 4, 8 So after four hours, it can be divided into 2 ^ (16-1) = 2 ^ 15.
Can the addition in the law of multiplication and distribution be replaced by subtraction for the letter expression of five operation laws and the expression of two properties?
Additive commutative law: a + B = B + A
The law of combination of addition: a + B + C = a + (B + C)
Commutative law of multiplication: a × B = B × a
The combination law of multiplication: a × B × C = a × (B × C)
The law of multiplicative distribution (applicable to addition and subtraction)
a×(b+c)=a×b+a×c
a×(b-c)=a×b-a×c