4 / 9 divided by x equals 4 / 7 (equation format)

4 / 9 divided by x equals 4 / 7 (equation format)

4 / 9 & x = 4 / 7, 4 / 9 = 4x / 7, 36x = 28x = 7 / 9

Among the five continuous natural numbers, the smallest one is equal to one sixth of the sum of the five numbers. What is the sum of the five numbers?

Let the minimum number be x, then
6x=x+(x+1)+(x+2)+(x+3)+(x+4)
x=10
The sum of these five numbers is 60

In 6 of a (a is a non-zero natural number), when a equals (), this fraction is the largest

When a = 1,

Who can tell me the Lagrange mean value theorem, Cauchy mean value theorem and Rolle theorem in the most easy way? When are these applied?

The key point of the three mean value theorems lies in the construction function. Rolle's theorem means that the values of the continuous differentiable functions in the function interval are equal. The most important thing of Lagrange's theorem is that it is used to prove the existence of continuous inequality. The main sign is that it is generally used to prove the formula with continuous inequality

The density p (kg / m ^ 3) of a certain mass is the inverse function of its volume V (m ^ 3)

According to M = PV, the density p (kg / m ^ 3) of a certain mass of oxygen is the inverse proportion function of its volume V (m ^ 3), and the analytical formula is p = m / v

Define the operation, a + B = 3A + 4b, to know 7b = 45, then B =?
A、6 B、17/3 C、7

17/3

It's about weight and volume
There is a truck carrying coal, with 50 cars. One car is 10 meters long and 2.8 meters wide from the inside, and the coal inside is 1.5 meters high. If 0.78 cubic meters of coal weighs 1 ton, how many tons of coal does this train transport? (the number is reserved to one decimal place)

Coal loading volume of each carriage: 10 * 2.8 * 1.5 = 42m3
Coal loading volume of 50 cars: 42 * 50 = 2100m3
Total weight: 2100 / 0.78 = 2692.3 tons
A total of 2692.3 tons of coal were transported

Light year is the distance unit used in astronomy, which is mainly used to measure the distance of extrasolar objects. 1 light year refers to the distance that light travels in vacuum for one year, and the speed of light in vacuum is about 3 * 10 to the fifth power of km / s

15 billion light years = 1.5 × 10 10th power light years
1 light year = 5 power of 3 × 10 × 365 × 24 × 3600 = 12 power of 9.4608 × 10 km
15 billion light years = 1.5 × 10 to the 10th power × 9.5 × 10 to the 12th power = 1.41912 × 10 to the 23rd power km
Please take the answer and support me

Is pi approximate or accurate

Approximate value. I remember reading an article before that the United States used large-scale computers to calculate hundreds of millions of decimal places in more than a year

The problem of surface area of space geometry in senior one
The bottom radius of a cone is 5cm and its height is 12cm. When the bottom radius of its inscribed cylinder is what, what is the maximum area of its inscribed cylinder?

Let the radius of the base of the inscribed cylinder of the cone be x, then 0