Accounting Wang found that the cash was 153.9 yuan less when he kept the account. After checking the account, he found out that the decimal point of an expenditure was wrong. Accountant Wang found out that the wrong expenditure was actually______ Yuan

Accounting Wang found that the cash was 153.9 yuan less when he kept the account. After checking the account, he found out that the decimal point of an expenditure was wrong. Accountant Wang found out that the wrong expenditure was actually______ Yuan

We found out that the actual expenditure of Wang Yuan was 10 yuan,
Then 10x-x = 153.9,
The solution is x = 17.1
Then accountant Wang found out that the wrong expenditure is actually 17.1 yuan
So the answer is: 17.1

What is the value of (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10) × 10

Five hundred and fifty

2. A mountain road. It takes only 150 minutes for someone to walk from the top of the mountain to the bottom of the mountain. It is known that the speed of going down the mountain is 1.5 times of the speed of going up the mountain. If the speed of going up the mountain is Z km / min, the equation is given as follows 3. If a goes 16 minutes at the speed of 5 km / h, and B pursues a at the speed of 13 km / h, the time required for B to catch up with a is () A 10 hours B 6 hours C one sixth hour D 80 minutes of 13 hours 4. When the car drives on the highway at a speed of 72 km / h, the driver turns on the horn and hears the echo after 4 seconds. How far is the car from the valley? It is known that the propagation speed of sound in the air is about 340 m / s. when the echo is heard, the car is x m away from the valley. According to the meaning of the question, the equation is listed as follows

1. No equation, only polynomial 150 × 1.5z
2.C
3.X+20×4+X=340×4
X=640

1 2 3 4 5 6 7 8 9=126 You can only fill in brackets, plus sign and multiply sign in the middle

1+2*3+4*5+6*(7+8)+9=126
（1+2)*(3+4+5+6+7+8+9）=126

A mathematical problem. There are 25 numbers. They are 5 1 5 2 2 3 2 4 2 5 1 6 2 8 1 9 1 10 1 11. 6 of them are optional How many permutations and combinations make the sum of them equal to 44, and what are the differences Four 7's missing and 26 digits

Addition is usually done by observation
It is observed that 6 + 8 + 9 + 10 + 11 = 44, of which 6 9 10 11 has only 1, so there is no larger number than 9 to replace. Only 1 number can be added, so only 2 of them can be replaced at most. If 3 numbers are replaced, it is not enough 44
Replace one with two numbers
Replace 6
6 = 1 + 5 = 2 + 4 = 3 + 3
Replace 8
There are three kinds of 8 = 1 + 7 = 3 + 5 = 4 + 4
Replace 9
9 = 5 + 49 = 1 + 8 9 = 2 + 7
Replace 10
10 = 5 + 510 = 2 + 8 10 = 3 + 7
Replace 11
11 = 3 + 8 11 = 4 + 7
Replace 2
Only 6 + 8 can be replaced
6 + 8 = 7 + 7 1 species
The rest is replaced by 9 10 11
There are 1 * (4 + 4 + 3) = 11 species
There are 25 species of 3 + 3 + 3 + 3 + 2 + 11

Little doctor skillfully solving problems 1-2-3 + 4 + 5-6-7 + 8 + 9-10-11 +... + 1997-1998-1999 + 2000

We can see from the title:
1-2-3+4=0
5-6-7+8=0
9-10-11+12=0...
That is to say, the first number minus the two consecutive numbers plus the following number is 0
So the original formula = 0

How to calculate the math problem easily 1.1 + 2.1 + 3.1 + 4.1 + 5.1 + 6.1 + 7.1 + 8.1 + 9.1 =?

simple form
=（1+0.1）+（2+0.1）+...+（9+0.1）
=（1+2+...+9）+（0.1×9）
=（1+9）×9÷2+0.9
=45+0.9
=45.9
Your adoption is the driving force of my answer!

A mathematical problem | 1-1 | 2 | + | 1 | 2-1 | 3 | + | 1 | + | 5-1 | + | 1 | + | 7-1 | 8 | + | 1 | 9 + 1 | |1\99-1\100|

|1-1\2|+|1\2-1\3|+|1\3-1\4|+|1\5-1\6|+|1\7-1\8|+|1\9-1\10|… |1\99-1\100| =(1-1/2)+(1/2-1/3)+…… +(1/99-1/100) =1-1/100 =99/100
Hope to adopt

1 + 2 + 3-4-5-6 + 7 + 8 + 9-10-11-12 + 13 + 14 + 15 Mixed operation of addition and subtraction of rational number

The original formula = (1-4) + (2-5) + (3-6) + (7-10) + ＋(2007-2010)=-3×（2010÷2）=-3015.

4 and 9 / 7 + 1.7 + 5 / 9 2 + 8 and 10 / 3 = how much

4 and 9 7 + 1.7 + 5 and 9 / 2 + 8 and 3 / 10
=4+7/9+1+7/10+5+2/9+8+3/10
=4+1+5+8+7/9+2/9+7/10+3/10
=18+1+1
=20