There are four classes in Grade 6 participating in tree planting activities. The number of trees planted in class 1 accounts for 20% of the total number, and the number of trees planted in class 2 accounts for 14% of the total number. The ratio of the number of trees planted in class 3 to class 4 is 5:6. It is known that class 1 plants 12 fewer trees than Class 2, and how many trees are planted in class 3?

12 △ 14-20%, = 12 △ 5%, = 240 (trees); 240 × (1-20% - 14), = 240 × 55%, = 132 (trees); 132 × 55 + 6, = 132 × 511, = 60 (trees); a: 60 trees in class three

What is 9.9 times 5.6 plus 0.56

9.9*5.6+0.56
=9.9*0.56*10+0.56
=99*0.56+0.56
=0.56*(99+1)
=0.56*100
=56

How many donations have you received so far after the 5.12 Wenchuan earthquake?

Recommended 41742000000 yuan
There are many unsung heroes who directly transfer money to the Red Cross account. There are also some overseas Chinese. I believe there are many rich patriots who also take this way. Therefore, the total number is always a mystery
However, there is an official number released by the Ministry of civil affairs as of February 12, 2009
A total of 41742000000 yuan was donated to the disaster area by all walks of life at home and abroad

What are 1 cubic centimeter objects, and 1 cubic decimeter, meter. Milliliter. Liter

Lard with gasoline, diesel and lard in liters
Correction paper in cubic centimeter with fingers over toes and a Gobang

Answers to the winter vacation homework in the first semester of grade one of Hongling middle school (Shenzhen, Guangdong)
Before the 25th, I gave you more points

En. You are so handsome. Ask the answer in Baidu
Teach you a method, although it is wrong
When you leave school for a week or so, go to the library or McDonalds KFC or other places, you will find a lot of copy homework, and then ask others~

A green area of 5 * 10 ^ 4 square meters is planted with oleander, weeping willow, Euonymus japonicus and other green plants. They have strong absorption capacity for harmful gases and can purify the air. In sunny days, the leaves of each square meter usually absorb about 2.5 grams of sulfur dioxide, nitrogen dioxide and other harmful gases every day, How many tons of harmful gases can this green area absorb in a month (30 days)

2.5*5*10^4*30=3.75*10^6 g=3.75t

How many kilograms is a liter of diesel equal to

We need to know the density of diesel oil. It is affected by the quality and air pressure. At present, the average value is mostly 0.84. That is to say, 1 liter of gasoline = 0.84 kg. 1 ton of diesel oil = 1000 / 0.84 = 1190 liters

It's better for unit one,

1、 Fill in the blanks (30 points) 1. The sum of 230 and 250 minus the quotient of 720 divided by 80, the difference is 9 (). 2. The product of multiplication of two numbers is 460. If one factor expands ten times and the other shrinks ten times, then the product is the product of (). 3. 25 and 18 minus the quotient of 840 divided by 5, what is the difference? The formula is (). 4

89 of a number is less than 2 of the product of 18.5 and 45

Let this number be X. from the meaning of the question, we can get: 89x = 18.5 × 45-2, 89x = 14.8-2, 89x = 12.8, & nbsp; X = 14.4; a: this number is 14.4

How to calculate 63 * 57
1.63*57
2. (2x + 3Y) square

1、
simple form
=（60+3）×（60-3）
=60²-3²
=3600-9
=3591
2、
simple form
=4x²+12xy+9y²