A kind of children's story book was delivered to the bookstore. It sold 30% on the first day, and 120% on the second day, 30 more than the first day. How many of these story books were delivered to the bookstore?

A kind of children's story book was delivered to the bookstore. It sold 30% on the first day, and 120% on the second day, 30 more than the first day. How many of these story books were delivered to the bookstore?

30% × 120% - 30%, = 30% × 6%, = 500 copies; a: there are 500 copies of this kind of story books from the bookstore

The bookstore delivered a kind of children's story book, which sold 30% on the first day and 120% on the second day, 30 more than the first day. How many story books did the bookstore deliver?
What does 30% x 120% = 36% mean? What's going on?

36% refers to 36% of the books
30%x120%=36%
36%-30%=6%
30 △ 6% = 500 (this)
A: a total of 500 story books were delivered to the bookstore

A kind of children's story book was delivered to the bookstore. It sold 30% on the first day, and 120% on the second day, 30 more than the first day. How many of these story books were delivered to the bookstore?

30% × 120% - 30%, = 30% × 6%, = 500 copies; a: there are 500 copies of this kind of story books from the bookstore

How to divide the square of M minus 2m plus 1 divided by 1 minus the square of M

The first half is obviously the expansion of the square of (m-1), so the answer is the square of (m-1) / m

Find a general term formula of the following sequence of numbers: Question 1 2 / 3,4 / 9,9 / 27,16 / 81,32 / 243, ··· question 2 - 1 / 1 × 3,1 / 2 × 4, - 1 / 3 × 5,1 / 4
Then - 1 / 5 × 7···
Question 3 4,10,28,82,44···

1. (2) nth power / (3) nth power has some problems with the third number
2. (- 1) nth power / N (n + 2)

If x divided by Y equals 13 (x, y are integers), then the greatest common factor of X and Y is (), and the greatest common multiple is ()

The common factor Y and the common multiple are X

The solution of the equation a (x + m) 2 + B = 0 of X is X1 = - 2, X2 = 1 (a, m, B are all constants, a ≠ 0), then the solution of the equation a (x + m + 2) 2 + B = 0 is______ ．

∵ the solution of the equation a (x + m) 2 + B = 0 about X is X1 = - 2, X2 = 1, (a, m, B are all constants, a ≠ 0), ∵ the equation a (x + m + 2) 2 + B = 0 is transformed into a [(x + 2) + M] 2 + B = 0, that is, in the equation x + 2 = - 2 or x + 2 = 1, the solution is x = - 4 or x = - 1. Then the solution of the equation a (x + m + 2) 2 + B = 0 is X1 = - 4, X2 = - 1

0.75 = (): 8 = 16 points () = 9: () = () points ()

It is known that the solution of the system of equations x + y = m, 5x + 3Y = 31 about X, y is nonnegative, and the value of integer m is obtained

X + y = m (1) 5x + 3Y = 31 (2) (2) - (1) * 35x + 3y-3x-3y = 31-3m2x = 31-3mx = (31-3m) / 2Y = M-X = m - (31-3m) / 2 solution XY are all nonnegative numbers x ≥ 0, (31-3m) / 2 ≥ 0,31-3m ≥ 0,3m ≤ 31, i.e. m ≤ 31 / 3Y ≥ 0,m - (31-3m) / 2 ≥ 0,2m-31 + 3M ≥ 0,5m ≥ 31, i.e. m ≥ 31 / 5 ≤ M

() * 5 / 9 + 4 / 9 divided by 8 = 19 / 18
English: how many times 5 / 9 plus 4 / 9 divided by 8 equals 19 / 18?

Interesting! The answer is 9 / 5 = 1.8