After listening to the report, I learned a lot of truth

After listening to the report, I learned a lot of truth

This report has taught me a lot of truth
or
After listening to the report, I learned a lot of truth
Our teacher just said, please take it

After listening to the report, we learned a lot of truth

After listening to the report, we learned a lot of truth
I am a Chinese teacher

12 and 1 / 3 times 11 and 2 / 3 =? Square difference

12 and 1 / 3 times 11 and 2 / 3 =?
=（12+1/3)*(12-1/3)
=12²-(1/3)²
=144-1/9
=143 8 / 9

Brief calculation of 2005 * 2005-2004 * 2004
Keep it simple. Don't take too much trouble

2005²-2004²
=(2005+2004)(2005-2004)
=4009

Given a = a + 2, the quadratic power of B = a - A + 5. C = A & # 178; + 5a-13, where a > 2, what is the value of b > C

The second power of B = a - A + 5. C = A & # 178; + 5a-13
The second power of a - A + 5 > A & # 178; + 5a-13
6a

1.6 plus 23.4 divided by 7.2.07 divided by 0.23 divided by 0

1.6 plus 23.4 divided by 7.2
1.6+23.4÷9÷0.8
=1.6+2.6÷0.8
=1.6+13÷4
=1.6+3.25
=4.85
2.07 divided by 0.23 divided by 0.45
=2.07÷0.9÷0.5÷0.23
=2.3÷0.23÷0.5
=10÷0.5
=20

When m is an integer, are the roots of the equation MX ^ 2 - (2m + 1) x + m + 1 = 0 integers?

First, the equation can be written as [MX - (M + 1)] (x-1) = 0
So the solution of the equation is X1 = 1, X2 = (M + 1) / M = 1 + 1 / m
To make x2 an integer, that is, m must be equal to 1
In addition, when m = 0, the equation becomes one variable linear equation 1-x = 0, only one root x = 1, which also meets the requirements

15 divided by 9 (1 / 5 minus 1 / 3) =?

=(15×1/5-15×1/3)÷9
=(3-5)÷9
=-2 / 9

A rectangular wooden box is 84 decimeters long, 54 decimeters wide, 34 decimeters high and 2 decimeters thick. What is the volume of this wooden box?

The sky without clouds,
The internal length is: 84-2 × 2 = 80 (decimeter)
The inner width is 54-2 × 2 = 50 (decimeter)
The internal height is 34-2 × 2 = 30 (decimeter)
Volume of wooden case: 80 × 50 × 30 = 120000 (cubic decimeter)

If a three digit number is divided by 37, the remainder is 17, divided by 36, and the remainder is 3, then the three digit number is 3______ ．

Let the quotient of a three digit number divided by 37 and the remaining 17 be a, then the three digit number can be written as: 37 × a + 17 = (36 + 1) × a + 17 = 36 × a + (a + 17). Because "divide by the remaining 3", so (a + 17) divided by 36 needs the remaining 3, and the quotient can only be 22. Therefore, the three digit number is 37 × 22 + 17 = 831