Prime number 30 = () + () = () + () = () + () () = () + () () = () + () = () + ()

Prime number 30 = () + () = () + () = () + () () = () + () () = () + () = () + ()

30=10+20=15+15=12+18=16+14=25+5

30 = () + () = () + () + () prime number

11 19
2 11 17

Why is the rank of a row ladder matrix equal to the number of nonzero rows?
Such as the title

The matrix rank r means that there are subformulas of order r that are not equal to 0, and all subformulas of order r + 1 are 0. For convenience, we all talk about transforming the matrix into row ladder type. According to the most primitive formula, for example, the subformulas of several rows that are not 0 are definitely not 0. If we have all zero row pairs, it will be 0. For convenience of memory, sometimes we don't need to study very deeply. According to the definition, just find a simple example and remember it, It's very clear that I'm doing it myself!

The school organized a spring outing. There were 52 people going boating. They rented 11 boats, 6 people for each big boat and 4 people for each small boat,
They rented a big boat. How many boats are there?

Suppose it's all big ships
Then 11x6 = 66
66-52 more = 14
There are: 14 (6-4) = 7 boats
Ship 11-7 = 4

sin2x lim ------- x→0 tan3x

Is it LIM (x - > 0) sin2x / tan3x?
The method of equivalent infinitesimal (or the law of Robida) can be used
Original formula = LIM (x - > 0) 2x / 3x
=2/3

If f (x) satisfies f (1) = 2, f '(x) x ^ 2, what is the solution set?

f '(x)

What's the first class?
1. For example:
Section one
Section 2
Section 3
What should I say?
How to translate "Sub Zone 2 boundary" in the world time zone?
Is it a period or a class

1 the first class; the second class.
2 I'm not sure of it, suggest you find a map and later you will get the answer:)

How many meters is a kilometer?

One kilometer is 1000 meters

(3.2 x) × 14.3 △ 2 = 122.98 to solve the equation

（3.2+x）×14.3÷2=122.98
3.2+x=122.98×2÷14.3
3.2+x=17.2
x=17.2-3.2
x=14

Seeking English words with good meaning

What a hazy question! Give me some adjectives I like
Sentimental
Undefeatable never admit defeat
Keen
Vigor fresh
Enchanting