A rectangular iron plate, 30 cm in length and 25 cm in width. As shown in the figure, cut the square with a side length of 5 cm from four corners, and then make a box. How many ml is the volume of this box?

Because the length of the box is 30-5 × 2 = 20 (CM), the width is 25-5 × 2 = 15 (CM), and the height is 5 cm, the volume of the box is: 20 × 15 × 5, = 300 × 5, = 1500 (CC), = 1500 (ML); a: the volume of the box is 1500 ml

A 40 cm long, 30 cm wide rectangular iron sheet, four feet minus a side length of 5 cm square, make a uncovered rectangular iron box

Is it to find the volume of this iron box?
Do this: (40-5 * 2) * (30-5 * 2) * 5 = 3000 CC
Is it the surface area of this iron box?
Do this: 30 * 40-5 * 5 * 4 = 1100 square centimeters

The length of a rectangle is (x + 2) cm, and the width is 4cm less than the length. If the length and width of the rectangle are increased by 3cm, the area increases (?). If x is 3cm, the area increases (?)

Length = (x + 2), width = (x + 2-4) = (X-2), area = (x + 2) (X-2)
After increasing, length = (x + 2) + 3 = (x + 5), width = (X-2) + 3 = (x + 1), area = (x + 5) (x + 1)
Increased area = (x + 5) (x + 1) - (x + 2) (X-2) = 6x + 9
When x = 3, the increased area is 27

If the length of a rectangle is 5 × 10 to the third power and the width is 3 × 10 to the third power, its area is
The results were expressed by scientific counting

5x10^3x3x10^3=15x10^6=1.5x10^7

If the image of the straight line y = 2x + A and the image of the function y = 1 / 2x + 1 intersect in the second quadrant, then the value range of a,

Are both functions of first degree? Is the second y = 1 / 2 * x + 1
If so
(take the function as two equations to solve the intersection)
Simultaneous two equations
have to
x=2/3*(1-a)
y=4/3-1/3*a
And the intersection is in the second quadrant, so
The abscissa of the intersection is negative
The ordinate is a positive number
Namely
x=2/3*(1-a)0
The solution is 1

The function f (x) is defined in the interval [- 2,3], then the number of intersections between the image of y = f (x) and the line x = 2 is__
How to do it? I don't know what it means. Y = f (x)? His image can't be drawn at all? Straight line x = 2? How to draw this image? No Y

If you look at the definition of a function, you will find that an X only corresponds to a Y, so when x = 2, there is only one value of Y corresponding to it, so there is only one intersection point. Remember the definition well

1. The function y = f (x) is defined in the interval [- 2,3], then there are several intersections between the image of function y = f (x) and the line x = 2
2. Let f (x) = LG (2 + x) / (2-x), then the domain of F (x / 2) + F (2 / x) is
3. If a = {x | y = log2 (MX ^ 2-2x + 2)}, B = {x | (2-x) √ X-1 / 2 ≥ 0} and a ∩ B = empty set, then the value range of M is given
4. In the plane rectangular coordinate system, O is the coordinate origin, the quadrilateral obcd is a parallelogram, the points B (1,0), C and D are in the first quadrant, | OD | = 2, ∠ BOD = 60 °, the moving straight line x = t moves parallel to the right from the Y axis, intersects the parallelogram at different two points m, N, and writes the analytical formula s (T) of the area s of △ omn expressed by T

1. It should be one, because the mapping from X to y stipulates that each x value can only correspond to one y value
2、1

It is known that the area of the triangle formed by the image of the first-order function y = half + B and the two coordinate axes is 1. The value of B is obtained

The area of the triangle formed by the image of y = x / 2 + B and the two coordinate axes is 1
And coordinate focus (0, b) (- 2b, 0)
|b|*|-2b|/2=1
We know that B = 1 or B = - 1

The image of the inverse scale function y = - 6 / X and the straight line y = - x + 2 intersects at two points a and B. the points a and B are in the fourth and second quadrants respectively. Find: 1. The coordinates of a and B. 2. The area of △ abo

(1) It is necessary to substitute y = - 6 / x into y = - x + 2
-6/x=-x+2
The solution is: X1 = 1 + √ 7, X2 = 1 - √ 7
Substituting X1 = 1 + √ 7 into y = - x + 2, y = - 1 - √ 7 + 2 = 1 - √ 7
Substituting x2 = 1 - √ 7 into y = - x + 2, y = - 1 + √ 7 + 2 = 1 + √ 7
And points a and B are in the fourth and second quadrants respectively
So the coordinates of point a are (1 + √ 7,1 - √ 7), and the coordinates of point B are (1 - √ 7,1 + √ 7)
(2) Let the analytic expression of line AB be y = KX + B and the intersection coordinate of X axis be c,
There are 1 - √ 7 = K (1 + √ 7) + B 1 + √ 7 = K (1 - √ 7) + B
By subtracting the above two formulas, we can get: k = - 1, and then we can get: B = 2
So the analytic expression of line AB is y = - x + 2, and the coordinate of point C is (2,0)
So s (. △ ABO) = s (. △ CBO) + s (. △ ACO)
=2*(｜1-√7｜)/2+2*(1+√7)/2=2√7

As shown in the figure, the point P (3a, a) is an intersection of the inverse scale function y = KX (k > 0) and ⊙ o, and the area of the shadow in the figure is 10 π, then the analytical expression of the inverse scale function is ()
A. y=3xB. y=10xC. y=12xD. y=27x

Let the radius of the circle be r. according to the symmetry of the circle and the symmetry of the inverse proportional function, we can get: 14 π R2 = 10 π solution: r = 210. ∵ point P (3a, a) is an intersection point of the inverse proportional function y = KX (k > 0) and ⊙ o.. 3a2 = K and (3a) 2 + A2 = R ∵ A2 = 110 × (210) 2 = 4. ∵ k = 3 × 4 = 12, then the analytical expression of the inverse proportional function is y = 12x

A rectangular iron plate, 30 cm in length and 25 cm in width. As shown in the figure, cut the square with a side length of 5 cm from four corners, and then make a box. How many ml is the volume of this box?