How many hours does it take for a plane to fly at a speed of 1000 meters per hour and 40 trillion kilometers?

How many hours does it take for a plane to fly at a speed of 1000 meters per hour and 40 trillion kilometers?

1 trillion = 10 ^ 12, 40 trillion km = 4 * 10 ^ 3 km
V = 1000m / h
V = 1000m / h, x = 4 * 10 ^ 13km
T = x / v = 4 * 10 ^ 13 / 1 = 4 * 10 ^ 13 hours

Find the tangent equation of the curve y = 2x & # 178; + 3 at the point corresponding to x = 1

y'=4x
Substituting x = 1, we get y = 2 + 3 = 5, k = y '= 4
So, the tangent equation is Y-5 = 4 (x-1)
That is: y = 4x + 1

One batch of goods, originally planned 8 times, actually only 5 times. How much more than originally planned?

The original plan is to transport 1 / 8 at a time
Actually, it's one fifth at a time
Then there is the formula: 1 / 5 - 1 / 8 = 3 / 40
three-fortieths

X + 5x-6 / 3x + 5 = x + 6 / a - X-1 / B to find the value of ab

Because x + 5x-6 equals (x + 6) (x-1), so 3x + 5 of X + 5x-6 equals 3x + 5 / (x + 6) (x-1)
X + 6 of a - X-1 of B is equal to a / x + 6 - / X-1, finishing a (x-1) - B (x + 6) / (x + 6) (x-1) again finishing (a-b) x - (6B + a)/
（x+6)(x-1)
Because x + 5x-6 / 3x + 5 = x + 6 / a - X-1 / b
So A-B = 3
6B+A=-5
A = 13 / 7
B=-8/7
So AB = - 104 / 49
What don't understand, can exchange ha

For a batch of flour, 2 / 5 and 3 / 7 of them were transported in the first time and the second time, respectively, and a total of 45 tons were transported in the two times
How many kilos are there

There are 45 △ (2 / 5 + 3 / 7) × 1000 = 54310 and 10 / 29 kg

On the necessary and insufficient condition a for the image of the linear function y = (- M / N) x + 1 / N of Y and X to pass through the first, third and fourth quadrants at the same time
On the necessary and insufficient conditions for the image of y = (- M / N) x + 1 / N to pass through the first, third and fourth quadrants at the same time
A .mn＜0
B.m＞0 ,n＜0

Because it passes through the first three or four quadrants, B < 0, k > 0, so - (M / N) > 0.1/n < 0, so N0

The number of school dance teams is between 30 and 40. The ratio of boys to girls is 4 to 5. How many people are there in this class?

I think this should be a math problem in grade 4 of primary school, right? It's said to set up unknowns upstairs. I'll give you a one without unknowns!
40 divided by (4 + 5) = 36 is so simple
Isn't this a difficult problem? Do you need unknowns?

Finding the range of function y = | x + 1 | + radical (X-2) & sup2
Note: the things in the root also include the square
Good answer. I'll add points

Y = | x + 1 | + radical (X-2) & sup2;
1.x=3
So all in all
The range is [3, positive infinity]

Boys account for 5 / 6 of the girls in the chorus, and then there are 3 girls, boys account for 5 / 12 of the total number of the chorus. How many boys and girls are there in the chorus?

Before the three girls, it was 15 boys and 18 girls. After the three girls, it was 15 boys and 21 girls
Set the original number of boys as 5x and girls as 6x
Then 5x / 5x + 6x = 5 / 12
Solve the equation and get x = 3
So the first three girls are 15 boys and 18 girls, and the last three girls are 15 boys and 21 girls

When x = 2, the value of the algebraic expression ax to the third power - 2 is 3. When x = - 2, the value of the algebraic expression is 3_____ .
List the formulas

When x = 2, the third power of the algebraic formula ax is 5. When x = - 2, there is a negative sign, that is, the third power of the algebraic formula ax is - 5, then subtract 2 to get - 7