Solve the equation X-1 / 6x = 5 x + 3 / 4x = 21 1 / 5x + 2 / 5x = 15

Solve the equation X-1 / 6x = 5 x + 3 / 4x = 21 1 / 5x + 2 / 5x = 15

1. X-1 / 6x = 5 5 / 6x = 5 x = 6 x = 6 x = 6 2. X + 3 / 4x = 21 7 / 4x = 21 x = 12 x = 12 3.1 / 5x + 2 / 5x = 15 3 / 5x = 15 x = 25 x = 25 x = 25

The problems of spring in Lesson 11 of Volume 1 of Grade 7
A picture of spring flowers
The spring breeze of ()
Spring rain chart of ()
1. If the coefficients of two terms of the same kind are opposite to each other, the combined result is______________ .
2. Dang K=__________ The sum of polynomial x ^ + XY + y ^ and polynomial 2x ^ - 3kxy - 3Y ^ does not contain XY term
(^ for square!)
Three, a, B two bags respectively contain the same kind of grain a kg and B kg (a > b), want to make two bags
How many kilograms of grain should be poured from bag a to bag B? For example, the grain in bag a is 100 kilograms,
The grain in bag B is 80 kg. In order to make the two bags contain the same amount of grain, how much should be poured from bag a to bag B
Kilogram of grain?
4. If x ^ + xy = 2, y ^ + xy = 7, what is the value of x ^ + 2XY + y ^
5. If a ^ - AB = 3, B ^ + AB = 2, what is the value of a ^ + B ^

When k = (1 / 3 3), the sum of polynomial x ^ + XY + y ^ and polynomial 2x ^ - 3kxy-3y ^ is not

A math problem in the first volume of seventh grade
Zhang Bin, a Chinese shareholder, bought 1000 shares of a company last Friday at 27 yuan per share
Monday, two, three, four, five
Up and down + 4 + 4.5 - 1 - 2.5 - 4 per share
It is known that Zhang Bin paid 1.5 ‰ of the handling fee when he bought the shares, and 1.5 ‰ of the turnover and 1 ‰ of the transaction tax when he sold them. If he sold all the shares before Friday's closing, how about his earnings? (the answer is 889.5 yuan,

First, calculate how much you spent on buying stocks:
27*1000*(1+1.5‰)=27040.5
Then calculate the share price at the time of sale:
27+4+4.5-1-2.5-4=28
The turnover at the time of sale is:
28*1000=28000
The actual amount of money gained after selling shares is:
28000*(1-1.5‰)*(1-1‰)=27930.042
Income minus expenditure is income
27930.42-27040.5=889.542

Addition and subtraction of integral (3)
Calculate the value of (the cubic power of 2A - the square of 3a, the square of b-2ab) - (the cubic power of a - the square of 2Ab + the cubic power of B) + (the cubic power of the square of 3a, the cubic power of B-A + the cubic power of B). But in the process of calculation, one student mistakenly wrote a = 56 as a = - 56, and another student mistakenly wrote B = - 28 as B = - 2.8, but the results of both of them are correct. Please find out the reason

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