The mathematics interest group held a test. There were 15 questions in the whole paper. It was stipulated that 8 points would be deducted for each right question and 4 points would be deducted for each wrong question. Xiaoying got 72 points in total, and she did it right______ Question

The mathematics interest group held a test. There were 15 questions in the whole paper. It was stipulated that 8 points would be deducted for each right question and 4 points would be deducted for each wrong question. Xiaoying got 72 points in total, and she did it right______ Question

The wrong questions are: (8 × 15-72) △ 8 + 4, = (120-72) △ 12, = 48 △ 12, = 4 (DAO); he did right: 15-4 = 11 (DAO); a: he did right 11 questions. So the answer is: 11

Xiaogang and Xiaoming have a 100 meter sprint race (assuming that their speed remains the same). When Xiaogang runs 80 meters, Xiaoming is still 25 meters away from the finish line. When Xiaogang reaches the finish line, how many meters is Xiaoming away from the finish line? What's the process

When Xiaogang ran 80 meters, Xiaoming ran 75 meters, and the speed ratio was 16:15. So when Xiaogang ran 100 meters, Xiaoming ran:
100 * 15 / 16 m, 100-100 * 15 / 16 = 25 / 4 = 6.25 m from the end

Xiaogang and Xiaoming are in a 100 meter race. When Xiaogang runs 80 meters, Xiaoming is 40 meters away from the finish line. When Xiaogang reaches the finish line, how many meters is Xiaoming away from the finish line?

Let Xiaoming be x meters away from the end
80：(100-40) = 100：x
The solution is x = 75
Or use arithmetic:
100 × (100-40) / 80 = 75 (m)

There are 2 yuan, 5 yuan and 10 yuan in total, 20 pieces, a total of 122 yuan, of which 2 yuan is as many as 5 yuan. How many pieces are 10 yuan?

Let the number of sheets of 2 and 5 be x, and the number of sheets of 10 be y. The following equation can be obtained: 2x + y = 20
2X+5X+10Y=122 X=6,Y=8

Find the rule and fill in: - 2, - 4,0, - 2,2 () ()

It's regular: minus two plus four, minus two plus four
-2 minus 2 equals - 4 - 4 plus 4 equals 0 0 minus 2 equals - 2 - 2 plus 4 equals 2 2 minus 2 equals 0 plus 4 equals 4
So the first bracket is 0 and the second bracket is 4

The general term formula of known sequence {an} is log2 [(n + 1) / (n + 2)], and if the sum of the first n terms is Sn, then the value of natural number n that makes Sn ≮ - 5 tenable is]
Given that the general term formula of sequence {an} is log2 [(n + 1) / (n + 2)], let the sum of the first n terms be Sn, then the value of natural number n which makes Sn ≮ - 5 hold is___
It's actually a multiple-choice question. A. has a minimum of 63 B. has a maximum of 63 C. has a minimum of 31
D. There is a maximum of 31

Analysis
Sn=log2*[(2*3*4*5*.*n+1)/(3*4*5*6*.*n+2)]
=log2(2/n+2)
So Sn = - 5 is equivalent to
2/n+2=1/32,
So n + 2 = 64,
n=62

Urgently seeking x ^ 2 / sqrt (a ^ 2-x ^ 2) indefinite integral

(-(x Sqrt[a^2 - x^2]) + a^2 ArcTan[x/Sqrt[a^2 - x^2]])/2

25 36 49 () 81 find the law 1 3 7 15 () 63 ()
fast
20: Give it to me by 56

25 36 49 (64) 81 increasing sequence, first increasing 11, then increasing 13, 15, 171 3 7 15 (31) 63 (127) increasing the square of 2, first 2, then 2 * 2, 2 * 2 * 21 + 2 = 33 + 2 * 2 = 77 + 2 * 2 * 2 = 1515 + 2 * 2 * 2 * 2 = 3131 + 2 * 2 * 2 * 2 = 6363 + 2 * 2 * 2 * 2 * 2 = 127

In X of 8 (x is a non-zero natural number), if it is a true fraction, X Max is (), if it is a false fraction, x min is ()?

In X of 8 (x is a non-zero natural number), if it is a true fraction, the maximum of X is (7); if it is a false fraction, the minimum of X is (8)

The smallest positive integer is (), the largest negative integer is (), the smallest natural number is (), and the smallest non negative integer
The smallest positive integer is (), the largest negative integer is (), the smallest natural number is (), and the smallest non negative integer is（

The smallest positive integer is (1), the largest negative integer is (- 1), the smallest natural number is (0), and the smallest non negative integer is (0)