Calculate 2 ^ 4 + log2 ^ 3

Calculate 2 ^ 4 + log2 ^ 3

2^4+ log2^3
=2^4× 2^log2^3
=16×3
=48

315 / (36% + 9%) simple method

To 315 / (5 * 9 * 0.01) = 700

The "H operation" of positive integer n is: 1. When n is odd, H = 3N + 13; 2. When n is even, H = n * 0.5 * 0.5 * (where h is an odd number). For example, the result of one "H operation" for number 5 is 28, that of two "H operations" is 7, and that of three "H operations" is 34. Then the result of 257 "H operations" is 28

257
Once = 3 * 257 + 13 = 784
Twice = 784 * 0.5 * 0.5 * 0.5 * 0.5 = 49
3 times = 3 * 49 + 13 = 160
4 times = 160 * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 = 5
5 times = 3 * 5 + 13 = 28
6 times = 28 * 0.5 * 0.5 = 7
7 times = 3 * 7 + 13 = 34
8 times = 34 * 0.5 = 17
9 times = 3 * 17 + 13 = 64
10 times = 64 * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 * 0.5 = 1
11 times = 3 * 1 + 13 = 16
12 times = 16 * 0.5 * 0.5 * 0.5 * 0.5 = 1 = the 10th time
So start from the 10th
An even number of times equals one
Odd times equal to 16
257 is odd
So 257th is 16

What's the number of the 9 th power of 2 plus the 29 th power of 13?

The n-th power of 2, the number of 2,4,8,6,2,4,8,6 bits in turn, every 4 cycles, is 2,4,8,69 / 4 = 2 So the single digit of the 9th power of 2 is the same as that of the first digit in the period, which is the nth power of 2.13 The number in one place

625:12 / 5

625:12 / 5
＝5/8×5/12
＝25/96
＝25：96

Summation method of sequence, such as accumulation, multiplication, dislocation subtraction, split term cancellation, etc

Accumulation: given a (n + 1) - A (n) = f (n); A1, then a (n) = a1 + F (1) + F (2) + F (3) + +f(n-1)
If a (n + 1) = a (n) * f (n); A1, then a (n) = A1 * f (1) * f (2) * f (3) * *f(n-1)
I don't understand the mathematical input method for the time being. Other input methods are too troublesome

What are the coordinates of the intersection of the functions y = x and y = 9 / x?

By solving the simultaneous equations, the intersection points are (3,3), (- 3, - 3)
Remember to adopt it

Find the greatest common factor of 30 and 45 by short division

So the greatest common factor of 30 and 45 is 3 × 5 = 15

If a and B are known to be greater than zero and a + 2b-2 = 0, then the minimum value of AB is 0

A + 2b-2 = 0A = - 2b + 2Ab = B (- 2b + 2) = - 2BB + 2B, this formula is regarded as a quadratic function of one variable, its coefficients are a = - 2, B = 2, C = 0 ∵ a < 0 ∵ it has the maximum value = (4ac BB) / 4A = (0-4) / - 8 = 1 / 2, that is, when B = - 2 / (- 2 * 2) = 1 / 2, AB has the maximum value of 1 / 2 (at this time a = 1)

Sum: S = 1 + 2x + 3x ^ 2 + 4x ^ 3 +. + NX ^ n-1 (x is not equal to 1)

S = 1 + 2x + 3x ^ 2 + 4x ^ 3 +. + NX ^ n-1 (x is not equal to 1)
XS=X+2X^2+3^3+.+(n-1)X^(n-1)+nX^n
subtract
(1-X)S=1+X+X^2+.+X^(n-1)-nX^n
=1*(1-X^n)/(1-X)-nX^n
S=(1-X^n)/(1-X)^2-nX^n/(1-X)