The first digit on the left of a six digit number is 1. If you move the number 1 to the far right, the six digit number will be three times of the original number. Find the original number. It must be equation ~ equation~ I hope you can answer it enthusiastically~

The first digit on the left of a six digit number is 1. If you move the number 1 to the far right, the six digit number will be three times of the original number. Find the original number. It must be equation ~ equation~ I hope you can answer it enthusiastically~

Let the original value be 100000 + X, (x is five digits)
Then move the number 1 to the far right, and the six digits are 10x + 1
10x+1=3（100000+x）
10x+1=300000+3x
7x=299999
x=42857
The original number is 142857

A mathematical problem solved by equation
There are several oranges, pears and apples in a basket. The number of pears is four fifths of the number of oranges, the number of apples is two thirds of the number of oranges, and the number of pears is three fourths less than two apples. How many fruits are there in the box

Suppose there are x oranges, 4 / 5x pears and 2 / 3x apples
The number of apples - 3 / 4 of pears = 2
2/3x－3/4×4/5x=2
2/3x-3/5x=2
1/15x=2
x=30
There are 30 oranges, 24 pears and 20 apples
There are 30 + 24 + 20 = 74 fruits in the frame

Xiaogang and Xiaoyu start from the dormitory building in the same direction at the same time. Xiaogang walks 98 meters per minute. After 15 minutes, they are 180 meters apart. Xiaogang is in front and Xiaoyu is behind. How many meters per minute can Xiaogang walk?
It's Xiaoyu, not Xiaogang

Light rain travels x meters per minute
（98-x）X15=180
1470-15x=180
15x=1470-180
15x=1290
x =1290÷15
x=86
A
Hope to help you.

A cuboid room is 3 meters wide and 6 meters wide. The lower part of its four walls is painted with 1.1 meters high paint (the door is 1 meter wide and not painted). How many square meters is the painted area

L x W x H - door area

There is a kind of energy-saving lamp used in 220 V power, the rated power is only 1 W, and the current is calculated
It's better to use the knowledge of electric power in grade two

P=UI
1w=220×I
I=1w/220V=0.0045A

（-a³）²×（-a²）³ （-3a）³-（-a）·（-3a）²

=a^6×(-a^6)×(-9a³)-9a³
=9a^15-9a³
=9(a^15-a³)

At a certain temperature, the density of the saturated solution of a substance with molar mass m is p
The mass fraction of solute in the solution is 0

This is the formula:
C= 1000*P* % /M
%= CM/1000P

What is the formula

Can you be more specific about your question? It's too general. According to the needs of the question, find out the corresponding relationship in the question. Many formulas can be listed at a time, and they can be replaced by the same amount

When the voltage at both ends of the conductor is 1V and the current is 1a, the conductor resistance is --- and the current is 0 when the voltage at both ends is 2V

First empty: r = u / I = 1V / 1A = 1 Ω
Second space: 1 ohm (the resistance of conductor can't be changed when the voltage changes)
What does "current is zero" mean,

1, known a + 1 / a = 2, find a ^ 2 + 1 / A ^ 2, guess a ^ n + 1 / A ^ n (n is any natural number) is equal to? And prove your conclusion
2. Calculation: 1 / (A-1) + 1 / (A-1) (A-2) + 1 / (A-2) (A-3) +... + 1 / (a-2004) (a-2005)
(process)

1. A + 1 / a = 2 square a ^ 2 + 1 / A ^ 2 = 2 conjecture a ^ n + 1 / A ^ n = 2
It is proved that a + 1 / a = 2 because a is not equal to 0
So a * a + 1 = 2A leads to a = 1
So a ^ n + 1 / A ^ n (n is any natural number) is equal to 2
2.1/[(a-n)(a-n+1)]=1/(a-n+1)-1/(a-n)
So 1 / (A-1) + 1 / (A-1) (A-2) + 1 / (A-2) (A-3) +... + 1 / (a-2004) (a-2005)
=1/(a-1)+1/(a-2)-1/(a-1)+1/(a-3)-1/(a-2)+...+1/(a-2005)-1/(a-2004)
=1/(a-2005)
=-1/2004