A commodity is priced at 20% profit and then sold at 20% discount, resulting in a loss of 128 yuan. What is the cost of the commodity______ Yuan

A commodity is priced at 20% profit and then sold at 20% discount, resulting in a loss of 128 yuan. What is the cost of the commodity______ Yuan

128 △ 1 - (1 + 20%) × 80%] = 128 △ 1-96%] = 128 △ 4% = 3200 yuan a: the cost of goods is 3200 yuan. So the answer is: 3200 yuan

Help! Math problem! Hurry up
In a test, there are 38 students in the class. There are 26 students in the first question and 20 students in the second question. Each student has at least one right question. How many students in the class do the second question

26 + 20 = 46, 46 people answered correctly,
Each person has at least one right question, a total of 38 people, and each person has one
So 46-38 = 8, 8 people answered correctly
There are eight students in the class doing two questions correctly

A few math problems ~ ~ ~ ~ help~
1. Pass through point P (2,1) to make the positive half axis of the x-axis and the positive half axis of the Y-axis of the line L intersect at two points a and B. when PA * Pb reaches the minimum value, the equation of the line L is solved
2. Given that the slope of the straight line L is 1 / 6, and the triangle area of the encirclement with the coordinate axis is 3, the equation of the straight line L is solved~
3. Given the function f (x) = {1 (x ≥ 0) 0 (x is less than 0), then the solution set of the inequality XF (x) + X ≤ 2 is?

1, assuming that the transverse intercept is m + 2 and the longitudinal intercept is n + 1,
Then n / 2 = 1 / m, that is Mn = 2
And PA * Pb = quadratic root {(n square + 4) * (m square + 1)} = quadratic root {m square * n square + (4 * m square + n square) + 4}
When 4 * m square = n square, i.e. n = 2, M = 1, the minimum value is obtained
The equation of the line L is x + y = 3
2, assuming that the equation is x / 6m-y / M = 1
(the cross section is 6m, the longitudinal section is - m, because the slope is 1 / 6, so the equation is assumed)
So area s = (1 / 2) * 6m ^ 2 = 3
So m = 1 or M = - 1
The linear equation is x-6y = 6 or x-6y = - 6
3. Discussion:
x> 2X at = 0

If the real number x, y satisfies the square of 2x - 6xy + 9y - 4x + 4 = 0
So what is the x power of Y?
If a + B = 6, the third power of a + the third power of B = 72, then what is the value of the second power of a + the second power of B?
There is another
Let a + B = 1, prove: the third power of a + the third power of B + 3AB = 1
It will be handed in soon

1. (x-3y) square + (X-2) square = 0, so x = 2, y = 2 / 3, so the x power of Y is equal to 4 / 92. Let the value of the second power of a + B be x, then the square of (a + b) is x + 2Ab = the third power of 36a + the third power of B = (a + b) (x-ab) = 72. The solution is x = 203. The third power of a + the third power of B + 3AB = (a + b) (the square of a - ab