A 60 meter long fence is used to form a rectangular flower bed. If the length is 3 meters less than twice the width, what is the area of the rectangle?

60÷2=30m
Set the width to x [you can set the length, but it's not easy, so it's better to set the width]
x+（2x-3）=30
3x=30+3
x=11
30-11=19m
11×19=209m
Er, the final result may not be right. I didn't use the computer to calculate So you'd better press the computer to check

A passage about peony and tulip

Heze peony has more than 1100 varieties, all kinds of color of Heze Peony have valuable varieties, such as "palm flower case" blooming like fire, red light, for the first red; "drunken Yang Fei" dressed in red, head down to hide his face, secretly send autumn waves; "pear snow" blooming like pear, snow-white, known as the white crown; "Kunshan night light" blooming strange white, night according to

The area and height of a triangle and a parallelogram are equal. Given that the bottom of a triangle is 20 cm, what is the bottom of a parallelogram?
A triangle and a parallelogram have the same area and height. Given that the bottom of a triangle is 20 cm, what is the bottom of a parallelogram? (it needs to be explained in detail,

S triangle = 1 / 2 s parallelogram, s triangle / height = 1 / 2 s parallelogram / 2
Triangle bottom = 1 / 2 parallelogram bottom
Parallelogram bottom = 10

The product of two prime numbers must be (). A. odd B. even C. composite D. prime

Choose C and add up
A. Odd number: 2 × 3 = 6, not odd number
B. Even number: 3 × 5 = 15, not even number
D. Prime number: impossible (a prime number can only be equal to 1 × itself, but 1 is not a prime number, which does not conform to the meaning of the question)

If the two sides of a triangle are 5cm and 8cm respectively, and the other side is () cm long (in meters)
If the two sides of a triangle are 5cm and 8cm respectively, and the other side is () cm long (in meters)
A / B / C are three different non-zero natural numbers. Given A-B = C, then the sum of a + B + C is () times of A
If the height of the cylinder is 8.4 cm, the height of the cone is () cm. If the height of the cone is 8.4 cm, the height of the cylinder is () cm

The first is 4, the second is 2, the third is 25.2, and the fourth is 2.8

As shown in the figure, PA is the tangent of circle O, the tangent point is a, Po intersects circle O at two points B and C, and PA = 2, Pb = 1, then the length of AB is______ ．

∵ PA is the tangent of circle O, the tangent point is a, Po intersects circle O at two points B and C, ∵ pa2 = Pb · PC, ∵ PA = 2, Pb = 1, ∵ PC = 4, BC = 3, ∵ PAB ∵ PCA, ∵ paab = PCCA, ∵ 2Ab = 49 − AB2, ∵ AB = 355

There is a section on both sides of a river that is parallel. There is a tree every 5 meters on this section of the river bank, and there is a telegraph pole every 50 meters on the other side of the river. When you look at the opposite bank 25 meters away from the bank, you can see that two adjacent telegraph poles on the opposite bank are just covered by two trees on this bank, and there are three trees between the two trees, so you can calculate the width of the river

As shown in the figure: AF = 25m, BC = 5 × 4 = 20m, de = 50m. Because BC ∥ De, BCDE = afag, that is 2050 = 2525 + FG, the solution is: FG = 37.5m. Through the test, FG = 37.5 is in line with the meaning. Therefore, the river width is 37.5m

① From point O to 5, four rays OA, ob, OC, OD, if ∠ AOB: ∠ BOC: ∠ cod: ∠ DOA = 1:2:3:4, what are the degrees of these four angles?
② As shown in the figure, ∠ AOB = 90 ° od bisection ∠ AOC, ∠ 3 = 3 ∠ 1, find ∠ 2
Writing process.. Thank you

∠AOB=（1+2+3+4）/360=36
∠BOC=2*36=72
∠COD=3*36=108
∠DOA=4*36=144
The second problem has no picture and no solution

Given the set a = {x | x-3x + 2 = 0}, B = {x | x-ax + A-1 = 0}, and a ∪ B = a, find the value of real number a

A x ^ 2-3x + 2 = 0, so x = 2 or 1 is a set ~ so a = {1,2} a ∪ B = a, so a is a subset of B, so 1,2 satisfies the equation 1 ^ 2-A * 1 + A-1 = 0, 2 ^ 2-A * 2 + A-1 = 0, the first equation is 0 = 0, the second equation is 4-2a + A-1 = 0, a = 3, so a = 3

A straight line L passes through the point P (- 4,3) and intersects the x-axis, Y-axis at a and B respectively, and AP: Pb = 5:3, find the equation of the straight line L
A straight line L passes through the point P (- 4,3) and intersects the x-axis, Y-axis at two points a and B, and AP: Pb = 5:3!

Because passing through point P, we can set the straight line as
y-3=k(x+4)
When y = 0, x = - 4-3 / k = a
When x = 0, y = 4K + 3 = B
ap:pb=|(-4+4+3/k)/(0+4)|=5/3
It can be solved that k = 9 / 20
So the equation is Y-3 = (9 / 20) (x + 4)
This is a point oblique form of a straight line without simplification

A 60 meter long fence is used to form a rectangular flower bed. If the length is 3 meters less than twice the width, what is the area of the rectangle?