The pear on the tree is green

The pear on the tree is green

The pears on the tree is green.

All formulas of mathematics compulsory 5

The basic properties of the arithmetic sequence are as follows: (1) the arithmetic sequence with the tolerance of D is still the arithmetic sequence, and the tolerance is still D. (2) the arithmetic sequence with the tolerance of D is still the arithmetic sequence, and the tolerance is KD. (3) if {a}, {B} is the arithmetic sequence, then {a ± B} and {Ka + B}

There are several triangles. Among all the internal angles, there are five right angles, three obtuse angles and 25 acute angles. How many acute triangles are there in these triangles

There are three acute triangles
An obtuse triangle must have 1 obtuse angle + 2 acute angles
A right triangle must have 1 right angle + 2 acute angles
So five right angles and three obtuse angles have to be matched with 16 acute angles
There are nine sharp corners left
It's three acute triangles

If x + 6xy = 16 and Y - 4xy = 12, then the value of X + 2XY + y is?

Formula 1: x + 6xy = 16,
Formula 2: y-4xy = 12,
So the value of X + 2XY + y is?
Formula 1 Plus Formula 2 is equal to:
X + 6xy + Y - 4xy = 16 + 12
X + y + 2XY = 28 (6xy-4xy = 2XY)
Above~

Xiaoming is 5 / 2 higher than Xiaoqiang. Xiaoming is twice as tall as Xiaoqiang. Xiaoqiang is 19 cm shorter than Xiaoming. How tall are they?

Xiaoming is 5 / 2 higher than Xiaoqiang, and Xiaoming is twice as high as Xiaoqiang,
First sentence: Xiaoming = Xiaoqiang × 5 / 2
The second sentence: Xiaoming = Xiaoqiang × 2
I don't quite understand Is Xiaoqiang = 0m; Xiaoming = 0.19M

Is capillary phenomenon the result of surface tension
Capillarity is the result of surface tension
Is that right

I'll try to answer it. Don't be surprised if it's not good^_ ^The phenomenon that the infiltrated liquid rises in the capillary tube and the phenomenon that the non infiltrated liquid decreases in the capillary tube is called capillary phenomenon. The tube that can produce obvious capillary phenomenon is called capillary. First of all, why can the liquid rise or fall in the capillary tube? We have known that the liquid

Solve
1. The maximum value of y = x ^ 2 (1-5x) in [0,1 / 5]
2. The maximum value of y = x ^ 2 (1-3x) in (0,1 / 3)
Ask to use inequality to solve Don't be derivative

1. The maximum value of y = x ^ 2 (1-5x) in [0,1 / 5]
x^2(1-5x)
=4/25[5x/2*5x/2*(1-5x)]

A classroom is 12 meters long and 8 meters wide. It should be drawn on a 1:400 scale plan______ Cm, width should be drawn______ Cm

Because 12 m = 1200 cm, 8 M = 800 cm, then 1200 × 1400 = 3 (CM), 800 × 1400 = 2 (CM); answer: length should be drawn 3 cm, width should be drawn 2 cm

A mathematical problem of filling in the blanks
There are 45 rubber and pineapples from the fruit shop. If the number of pineapples is 7 / 8 that of bananas, then there are () cases of pineapples and () cases of bananas.

If x boxes of bananas and 7 / 8x boxes of pineapples are transported, the following results can be obtained:
x+7/8x=45
15/8x=45
x=24
24 * 7 / 8 = 21 (case)
There are (21) cases of pineapples and (24) cases of bananas

How many questions about steel pipe weight calculation?
The diameter of iron pipe is 40 mm, 50 mm, 65 mm, 75 mm, 85 mm, the wall thickness is 3 mm, and the diameter of steel bar is 15 mm,

The volume of the iron pipe is v = pi * (R ^ 2 - (R-D) ^ 2) * l, D is the wall thickness of 3mm, l is the length of 1m. The mass m = V ρ, density ρ = 7.86g/cm ^ 3 is substituted into the calculation 40mm 2.74kg50mm 3.48kg65mm 4.59kg75mm 5.33kg85mm 6.07kg, the mass m = ρ * pi * R ^ 2 * l, density ρ = 7.85g/cm3 to calculate 1