It is known that the positive integer ABC satisfies the equation A & sup2; + B & sup2; + C & sup2; + 49 = 4A + 6B + 12C

It is known that the positive integer ABC satisfies the equation A & sup2; + B & sup2; + C & sup2; + 49 = 4A + 6B + 12C

a^2-4a+4+b^2-6b+9+c^2-12c+36=0
(a-2)^2+(b-3)^2+（c-6)^2=0
Because ABC is a positive integer, then a = 2, B = 3, C = 6

A correspondent rides a motorcycle to deliver the documents within the prescribed time. His speed is 36 kilometers per hour. As a result, he arrives 20 minutes earlier. If he is 30 kilometers per hour, he is 12 minutes late? What's the distance?

Suppose the specified time is x hours, according to the meaning of the question: 36 (X-13) = 30 (x + 15), the solution is: x = 3  36 × (3-13) = 36 × 83 = 96 km a: the specified time is 3 hours, and the distance is 96 km

Let m be a real number, a (Tan, 0), B (Tan, 0) be two points on the image of quadratic function f (x) + MX square + (2m-3) X-2, and find the minimum value of function y = Tan (a + b)

According to the meaning of the problem, Tana and tanb are two of F (x) = MX ^ 2 + (2m-3) X-2. According to Weida's theorem, Tana + tanb = (3-2m) / mtanatanb = - 2 / m ∧ y = Tan (a + b) = (Tana + tanb) / (1-tanatanb) = (3-2m) / (M + 2). Let m + 2 = t, then M = T-2, ∧ y = (3-2m) / (M + 2) = [3-2 (T-2)] / T = - 2 + 7 / T △ = (2m

Using a car to transport a batch of 12 tons of goods, 8 / 9 of this batch of goods are transported four times. What is the average percentage of this batch of goods transported each time?

Eight out of nine divided by four
The answer is two out of nine

If the square + 1 = 0 of the equation 2x ^ 3A about X is a linear equation of one variable, what is a = then

Since it is a linear equation of one variable with respect to x, then
3a²=1
a=±√3/3

There are 200 tons of yellow sand in a pile. 50 tons were transported away in the first time and 80 tons were transported away in the second time. How many parts of this pile of yellow sand were transported away in two times?
Because there is no unit behind the question, I think the answer is possible

It is (70 + 80) △ 150 = 3 / 4

Given the linear L1: y = 2x + 3, if L2 and L1 are symmetric about X axis, then L2 equation is

(0,3) and (1,5) are on line L1
Because L2 is symmetric about the X axis, the points corresponding to L2 are (0, - 3) and (1, - 5)
Let the line of L2 be y = KX + B
Then - 3 = B, - 5 = K + B
So k = - 2, so L2 is y = - 2x-3

There are 400 workers in the textile factory, among which there are 40 more female workers than 7 times of male workers

How did this come under the category of trade
If male workers are x and female workers are 7x + 40, then x + 7x + 40 = 400
Therefore, there are 45 male workers and 355 female workers

The length a, B, C of △ ABC three sides satisfy a & sup2; + B & sup2; + C & sup2; = AB + BC + ca. what is the relationship between △ ABC three sides?

a² +b² +c²=ab+bc+ca
2a² +2b² +2c²=2ab+2bc+2ca
2a² +2b² +2c²-2ab-2bc-2ca=0
(a-b)^2+(b-c)^2+(c-a)^2=0
a=b=c

There are four classes in Grade 6 of a school, with 50 students in each class. The ratio of boys to girls is 3:2. How many boys and girls are there?

50 × 4 = 200 (person)
Male: 200 × 3 / (3 + 2) = 120 (person)
Female: 200 × 2 / (3 + 2) = 80 (person)