The perimeter of a rectangle is 24 meters, and the meters of its length and width are prime numbers. How many square decimeters is the area of the rectangle?

Sum of length and width: 24 △ 2 = 12m
Because: 5 + 7 = 12 meters, 5 and 7 are prime numbers
Area: 5 × 7 = 35 square meters

In the plane rectangular coordinate system, through P (0,2), make a straight line intersecting with the parabola y = a (x ^ 2) and a greater than 0 at 2 points, and let the intersection point be a, B, ∠ AOB = 90 degrees
(1) Judge whether the product of a and B ordinates is a certain value, and explain the reason. (2) determine the analytic formula of parabola y = a (x ^ 2) and a greater than 0. (3) when the area of △ AOB is 4 √ 2 ￣, find the analytic formula of straight line ab

(1) Let a (x1, Y1), B (X2, Y2), because ∠ AOB = 90 degrees, so the slope product of AO and Bo is 1, that is: (Y1 / x1) * (Y2 / x2) = - 1, so Y1 * y2 = X1 * X2, and because Y1 = a (x1 ^ 2), y2 = a (x2 ^ 2), you can get X1 * x2 = - 1 / A ^ 2, so Y1 * y2 = 1 / A ^ 2 (2

How many tons is one cubic meter of concrete equal to

The density of ordinary concrete is 25kn / m3, that is 2500kg / m3
So a cubic meter of concrete is equal to 2.5 tons

It is known that the sum of polynomial x ^ 2-1 in a monomial is the complete square of an integer. Please find a monomial that satisfies the condition

x^2-1+1/(2x)^2=(x-1/2x)^2
The monomial is 1 / (2x) ^ 2

Calculate the curve integral of arc length
It's urgent.

X & # 178; + Y & # 178; = 9, the left semicircle is x = - √ (9 - Y & # 178;) such that x = 3cos θ, y = 3sin θ, π / 2 ≤ θ ≤ 3 π / 2DX / D θ = - 3sin θ, dy / D θ = 3cos θ DS = √ [x '(θ) &# 178; + y' (θ) &# 178;] d θ = √ (9sin & # 178; θ + 9cos & # 178; θ

How to calculate the theoretical weight of wire ropes of various specifications? Is there a unified method?

There is no unified method to calculate the theoretical weight of various specifications of steel wire rope, because there are many specifications of steel wire rope, especially the number of strands of steel wire rope, the number of thin steel wire in each strand, and the diameter of thin steel wire, which affect the winding angle of thin steel wire, as well as the influence of hemp rope in the middle

Given a = A & # 178; - 2Ab + B & # 178; b = A & # 178; + 2Ab + B & # 178; if 2a-3b + C = 0, then what is the expression of C

Your question is: if 2a-3b + C = 0, then the expression of C is? Because 2a-3b + C = 0, so 2 (A & # 178; - 2Ab + B & # 178;) - 3 (A & # 178; + 2Ab + B & # 178;) + C = 0, so C = 3 (A & # 178; + 2Ab + B & # 178;) + C = 0, so C = 3 (A & # 178; + 2Ab + B & # 178;) -

If the abscissa of point a on the parabola y ~ 2 = 2px is 4 and the distance from point a to the focus is 5, the parabolic equation is solved

P / 2 = 5-4 = 1, the solution is p = 2
So the parabolic equation y ^ 2 = 4x

How to convert liter to kilogram? How many kilogram is 18 liter of coating equal to

Volume for volume, CC is actually cubic centimeter, liter (L) is cubic decimeter, so 1 liter equals 1000cc, 1cc equals 0.001 liter. Liter is volume unit, kilogram (kg) is mass unit, they can not be directly converted, but can be calculated according to the formula mass = density × volume

225 times 4

The algorithm is as follows: 225x4 = (200 + 25) X4 = 800 + 100 = 900

The perimeter of a rectangle is 24 meters, and the meters of its length and width are prime numbers. How many square decimeters is the area of the rectangle?