My father is four times older than Xiaogang this year. Five years later, my father is 24 years older than Xiaogang. How old is Xiaogang five years later?

My father is four times older than Xiaogang this year. Five years later, my father is 24 years older than Xiaogang. How old is Xiaogang five years later?

24 / (4-1) = 8 years old; 8 + 5 = 13 years old
Five years later, Xiaogang was 13 years old

My father is four times older than Xiaogang. Five years later, my father is 36 years older than Xiaogang?

Set Xiaogang x years old, father 4x years old
The formula is as follows: (4x + 5) - (x + 5) = 36
The solution is x = 12
12 + 5 = 17, so Xiaogang will be 17 five years later

What is glacial acetic acid
Such as the title

Also known as acetic acid, that is, pure acetic acid, simple structure CH3COOH
Acetic acid is a colorless liquid with strong pungent smell. Its melting point is 16.6 ℃ and boiling point is 117.9 ℃. Pure acetic acid can form ice like solid below 16.6 ℃, so it is often called glacial acetic acid

I remember the quality, but I don't know

It's quality
Mg causes the object to bear gravity, and G is the acceleration of gravity
The general formula is f = ma, f causes the external force on the object, m causes the mass of the object, and a is the acceleration. (Newton's second law)

Isn't ln based on 10? How can it be written as ln based on e?

Ln is e
The log is 10

Which side is 160 degrees east longitude on 160 degrees west longitude

West
First draw a well character, then write the south latitude and north latitude directly, and then add the longitude. If it is greater than 180 degrees, east longitude is in the West and west longitude is in the East
The north-south direction is absolute, so the latitude does not change. While the east-west direction is relative, it should be counted as inferior arc. Therefore, if the longitude is greater than 180 degrees, the east longitude is in the west, and the west longitude is in the East

Let b > 0, the sequence satisfies A1 = B, an = [NBA (n-1)] / [a (n-1) + 2n-2] (n ≥ 2) (1) find the general formula of the sequence {an}; (2) prove that
Let b > 0, the sequence satisfies A1 = B, an = [NBA (n-1)] / [a (n-1) + 2n-2] (n ≥ 2)
(1) Find the general term formula of sequence {an};
(2) It is proved that for all positive integers n, an ≤ B ^ (n + 1) / 2 ^ (n + 1) ≤ 1

Limited by the number of words, can only say a train of thought
The title condition can be converted to
[(b^n)/(2^n)]*(n/a(n))=b^(n-1)/(2^n)+[b^(n-1)/(2^n-1)]*((n-1)/a(n-1))
Now it's simple

Y = | SiNx | the equation of symmetry axis of image is
Are there two?

X is equal to half of the k-pie and K is an integer

1 hour 60 minutes 3600 seconds, 1 day 24 hours equal to how many () minutes how many () seconds?

1440 minutes, 86400 seconds

Calculation (2 / 1 × 2 × 3) + (2 / 2 × 3 × 4) + (2 / 3 × 4 × 5) + (2 / 4 × 5 × 6) + +(2/99×100×101)+(2/100×101×102)

Original formula = 1 / 1 × 2-1 / 2 × 3 + 1 / 2 × 3-1 / 3 × 4 + +1/100×101-1/101×102
=1/1×2-1/101×102
=2575/5151