The total mass of a bottle filled with water is 64kg, the total mass of kerosene is 56g, the known bottle mass is 24g, and the kerosene density is calculated

The total mass of a bottle filled with water is 64kg, the total mass of kerosene is 56g, the known bottle mass is 24g, and the kerosene density is calculated

It's 64g, right
The quality of water is 40
The mass of kerosene is 32
The volume is the same, because it is the same bottle, so the density of kerosene is 32 / 40 of water = 0.8 times,
That is 0.8kg/m3
If you have to make a formula, make a formula

How many kilos of water can a bottle hold 1kg kerosene? (ρ kerosene = 0.8x10 cubic kg / m3)
I think it might be 1.25. If not, how to ask is the number

The answer is 1.25Kg of water

7200 (1 + x) 2 = 8450 solution

7200（1+X）^2=8450
50 (-1 + 12 X) (25 + 12 X)=0
x=1/12 x=-25/12

If the parabola y = ax ^ 2 + C intersects the X axis at points a and B, the vertex is C (0,4), and the area of triangle ABC is 8, find the triangle surrounded by the line y = ax-c and the coordinate axis
Urgent!! thank you!!

If the vertex is (0,4), then C = 4
Let ABC area of B (a, 0) triangle be 1 / 2x2ax4 = 8, a = - 1, so y = - x-4
The triangle area is 1 / 2x4x4 = 8

How to find the relationship between linear density and area density?

Linear density * length = area density * cross sectional area

How many numbers have the square difference of 195
There are two old people's age square difference is 195, there are two middle-aged people's age square difference is 195, there are two young people's age square difference is 195

It's factorization, 195 = 3 * 5 * 13, and then rounding up
A: 13 * 15, 14 and 1, the fourth pair
39 * 5, 22 and 17, young people
65 * 3, 34 and 31, middle-aged people
195 * 1, 98 and 97, the elderly
It's better

It is known that the line L passes through the focus F of the parabola y2 = 4x and intersects with the parabola at two points a and B. (1) if | AF | = 4, calculate the coordinates of point a; (2) if the inclination angle of the line L is 45 °, calculate the length of line ab

Let a (x1, Y1), B (X2, Y2). (1) from the definition of parabola, | AF | = X1 + P2, thus X1 = 3. Substituting y2 = 4x, the solution is Y1 = ± 23. The coordinates of point a are (3, 23) or (3, - 23). (6 points) (2) the equation of line L is y-0 = tan45 ° (x-1), that is, y = X-1 The two of them are x1, X2, and X1 + x2 = 6. From the definition of parabola, we can see that | ab | = P + X1 + x2 = 6 + 2 = 8. Therefore, the length of line AB is 8. (12 points)

How to calculate the weight of water according to the volume of water
The volume is 57 cubic meters. How many tons of water can it hold

I don't know whether your said weight unit is n or kg. If it is kg, use the formula:
V = m / ρ is calculated directly, where ρ = 1000kg / m3. In algebra, you can substitute 1000. M is the mass, that is, how many kg
If the weight is in N, divide the weight by 10 to get the mass kg, and then use the above formula to calculate

The principle of addition and the principle of multiplication
There are six different mathematics books on the first floor, five different Chinese books on the second floor, and four different English books on the third floor. If you take any six of these books, five of them are of the same kind, how many different ways are there?
(1) If 5 books are mathematics books, then 6 * (5 + 4) = 54
(2) If 5 books are Chinese books, then 1 * (6 + 4) = 10

When five books are for mathematics, that is to say, there are six ways to take five books from mathematics books, and there are five + four ways to take the remaining one from Chinese and English books
Five are Chinese books

Given the function f (x) = X4 + ax-lnx-32, where a ∈ R, and the tangent of curve y = f (x) at point (1, f (1)) is perpendicular to the straight line y = 12x. (I) find the value of a; (II) find the monotone interval and extremum of function f (x)

(I) f (x) = X4 + ax-lnx-32, ∵ f ′ (x) = 14-ax2-1x, ∵ curve y = f (x) tangent at point (1, f (1)) is perpendicular to the straight line y = 12x. ∵ f ′ (1) = 14-a-1 = - 2, the solution is: a = 54, (II) from (I) know: F (x) = X4 + 54x-lnx-32, f ′ (x) = 14-54x2-1x