PEP sixth grade volume I exercise 4 look at the picture and write the model essay It's urgent,

There is only one day on November 5, 2011
I want to write it by myself. Forget it. I'll write it tomorrow,

In recent years, the global weather has become abnormal, global warming is becoming increasingly serious, and the main culprit of the greenhouse effect is caused by the emission of a large amount of carbon dioxide in human activities. Many scholars have begun to study how long the life of the earth is left, what makes our beautiful earth change

The number a is 100, the number B is 60% of the number a, and the third quarter of the number C is the number B. the average of the three numbers is ()

Is the rank of the augmented matrix equal to or greater than the rank of the coefficient matrix in linear algebra

If a is an M × n matrix and R (a) = n, then AX = B (a) a, may have a solution; B, must have a unique solution; C, must have no solution; D, must have infinite solutions

It is known that it takes the same time for Party A to make 360 parts and Party B to make 480 parts. They make 140 parts a day. Let Party A make x parts a day
A. 360x＝480140−xB. 360140−x＝480xC. 360x+480x＝140D. 360x−140＝480x

Let a make x parts every day, according to the meaning of the question: 360x = 480140 − X; so choose a

Three X - one in nine = eight in nine how to solve this equation

3x-1 / 9 = 8 / 9
3x = 1 / 9 + 8 / 9
3x=1
X = 1 / 3

The storage of grain in warehouse A is 42.8 tons, and that in warehouse B is 27.2 tons. How many tons of grain are transported from warehouse B to warehouse a can make the storage of grain in warehouse a three times of that in warehouse B

1. 42.8 + 27.2 = 70
2. 70 △ 4 = 17.5 (divided into four parts to ensure three to one, i.e. three times)
3. 27.2-17.5 = 9.7
9.7 is the quantity to be shipped out

7x+2x=0.81 4(x-6)=36 2x+0.2xX2=36 3.4x-6=4.2 7.8x+5=44 7.5x+2.5=20 25.8-2x=12-7 4x+2.8=5.04
0.9x-4X1.3=1.1 1.3x7=25.1-8x 4.8+0.5x=6.3 (25+2x)X4=340
The capital x is multiplied by the lowercase X. how many times is x

(1)7x+2x=0.819x=0.81. x=0.9(2)4(x-6)=36x-6=9. x=15(3)2x+0.2x*2=362.4x=36. x=15(4)3.4x-6=4.23.4x=10.2. x=3(5)7.8x+5=447.8x=49. x=245/39(6)7.5x+2.5=207.5x=17.5. x=7/3(7)25.8-2...

10% of 13 (3 / 4 + 1 divided by 5 / 6) and 10.15-6.25-3.75 + 7.85

10% of 13 (3 / 4 + 1 divided by 5 / 6)
=10/13 * 5/2
=13/25
10.15-6.25-3.75+7.85
=10.15+7.85-(6.25+3.75)
=18-10
=8

It is known that the sum of the first five terms of the positive proportional sequence is 3, the sum of the first 15 terms is 39, and the sum of the first 10 terms is?

Because it is an equal ratio sequence, S5, S10 - S5, S15 - S10 are equal ratio sequences
That is, if 3, s10-3 and 39-s10 are in equal proportion sequence, there will be
(s10-3) ^ 2 = 3 (39-s10), the solution is: S10 = 12 or - 9 (rounding), that is, S10 = 12

PEP sixth grade volume I exercise 4 look at the picture and write the model essay It's urgent,