What does ln mean in the formula of average temperature difference

What does ln mean in the formula of average temperature difference

Is a logarithm based on e (a constant)
For example, e ^ 2 = a - > ln (a) = 2

What is ln (- 1) equal to?

Hello!
The domain of y = LNX is x > 0
So ln (- 1) is meaningless

Is zero greater than all negative numbers?

Greater than

A = 2 × 3 × a, B = 2 × 5 × a, if the greatest common factor of a and B is 14, then a is (); if the least common multiple of a and B is 120

A = 2 × 3 × a, B = 2 × 5 × a, if the greatest common factor of a and B is 14, then a is (7); if the least common multiple of a and B is 120
Then a = 4

A right angle side is 9 decimeter isosceles right triangle, how does its area calculate?
The hospital cuts a 45 decimeter long, 18 decimeter long rectangular white cloth into a right angle with 9 decimeter sides. How many pieces can it cut into if you want a right triangle?

Its area is the product of two right angle sides
That is, s = (9 × 9) △ 2 = 40.5 (square decimeter)
The area of original white cloth is 45 × 18 (square decimeter)
Now we need to make (1 / 2) * (9 × 9) right triangle cloth
Let the number of blocks that can be made be x, then x = 45 × 18 △ [(9 × 9) / 2] = 20 (blocks)
A: it can be cut into 20 pieces of right triangle cloth with 9 × 9 right angle sides

2 / 3 of the number a is equal to 3 / 4 of the number B, and the number a is a fraction of the number B

3 / 4 △ 2 / 3 = 3 / 4 × 3 / 2 = 9 / 8 (9 / 8)

How to prove that AX = B has no solution if and only if rank a + 1 = rank (a, b)?

Consider the inequality R (a)

Party A and Party B process one kind of parts at the same time. Party A processes five parts in six hours and Party B processes three parts in four hours. Which one of them is more efficient?

A5 / 6 = 5 / 6 = 10 / 12
B 3 △ 4 = 3 / 4 = 9 / 12
So the efficiency of a is high

7x-3y/5=5x-y/3-x+y/2 x-1/5=y+1/3

First, transfer the first formula to 7x-5x + x = 3Y / 5 + Y / 2-y / 3 (right general)
We get x = 23y / 90 (1)
Multiply both sides of the second formula by 15 to get 15x = 15y + 8 (2)
Put (1) into (2) to get the result of their own calculation ah!

Three warehouses hold 1400 grains. A is 3:4 of B, B is 6:7 of C,

Let C be X
x+6/7x+9/14x=1400
35/14x=1400
5/2x=1400
x=560
It is 560 for C, 480 for B and 360 for a