Ask for answers to practical problems! It s simple, a few application problems, solve!

If not, let's just set the unknown, it's simple.

Oh, for this kind of question, you have to find more relationships! Thinking about this rectangle, the length is known to be 20cm, and the width and height are unknown, but we know the ratio of length, width, and height, so we use this ratio to set the unknown.

Suppose the length is 5x, the width is 4x, and the height is 2x, since 5x=20, so x=4 width is 4x=4*4=16, and height is 2x=2*4=8 Think about it, a rectangle has 4 lengths, widths, and heights.

So: The total length of all edges is 4*(20+16+8)=176cmSurface area: 2*(20*16+16*8+8*20)=1216cm2Volume : 20*16*8=256cm3

I think if you're unfamiliar with this kind of question, it's best to find a few boxes and open them yourself, and good luck!

Length 20cm, width 20 5 * 4 = 16cm, height 20 5 * 2 = 8cm The sum of the edge length is 20 + 16 + 8 = 44cm

The surface area is 2 (ab + bc + ac) = 2 (20 * 16 + 20 * 8 + 16 * 8) = 1216 cm 2

The volume is abc = 20 * 16 * 8 = 2560 cm 3

Solution: Because the ratio of length, width, and height is 5:4:2, so let's set 5x:4x:2x because 20cm=

So so x=

So width = height =

Total length of all edges: 4*(

Surface Area: (Volume; Square metre.

Again, that's it

1.Solution: Let the odd number in the middle be x. The liquid lease side refers to the leakage range, x-2)+x+(x+2)=129

3x=129x=43

A: They donated 41 yuan, 43 yuan, and 45 yuan respectively.

I can't understand the last two questions...

The first question is boring, the bend is 139, the second question is 48 people staring forward, it can be 7 lines, it can be 3 lines, and the third question is a square with a side length of up to 7cm, and 96 squares can be cut.

1): Let the odd number of the middle state pie be x, then the three numbers are x-2, x, x+2 then: x-2+x+x+2=129, then x=43,41,43,45 (2) 6*8=48 people, there are 1,2,3,6,7,14,21 lines before dressing, 7 kinds of books are absent (3) 28cm, 2*3=6.

1) Let the pear tree have x trees, and get the equation according to the meaning of the question:

240=x*（1+2/3）

The solution is x=144 (trees).

2) Let there be x apple trees, and obtain the pure posture equation according to the meaning of the question:

x=144*(copy 1+2 3).

The solution is x=240 (trees).

two-thirds) = 240 five-thirds of the draft = 144 (trees).

Two-thirds of the key blocks the balance pants) = 144 five-thirds = 240 (trees).

1.One ton of waste paper can produce 700 kg of paper, if one kilogram of paper can make 25 exercise books, then how many exercise books can be made from 14 tons of waste paper?

700 14 25 = 245,000 copies.

2.The original area of a square was hectares, but now the area is 100 times larger than the original, how many hectares is the current area? How many square meters?

hectares = 67,000 square meters.

The area is now hectares. That's 67,000 square meters.

3.How many meters is the length of a 17-meter-long subway wire cut into 100 sections on average? How many centimeters?

17 100 = m = 17 cm.

Each segment is meters long. 17 cm.

(1) Percentage = ;

2) altogether=;

3) Altogether = kg = gram.

(1) kg:1 kg The decimal point is shifted to the right by two places at the same time = :100=(2) From the above question, we know that protein accounts for the total total nutrient content, so (3) From the above question, we know that these nutrients account for rice, so 200 grams of grams are expected to be adopted Thank you!

Xiaodong is right. The 3 4 of this book is 96 * 3 4 = 72 pages, which is 11 pages less than the 3 4 of this book, that is, 72-11 = 61 pages, and the title says that Xiaoyan read 35 pages, so the number of pages that she didn't read is (96-35) = 61 pages, so Xiaodong is right.

Number of pages not read: 96-35=61 (pages).

The book's 3 4 less 11 pages: 96x3 4-11 = 61 (pages) The book's 1 2 more 12 pages: 96x1 2+12=60 (pages) Xiaodong is right.

96-35 = 61 pages, and 61 more pages Mu has to read, for Xiaodong: 3 4 in this book is 96 3 4 = 72 pages, 61 is 11 less than 72, so Xiaodong is right.

For Xiaoling: 1 2 in this book is 96 1 2 = 48 pages, 61 is 13 more than 48, so Xiaoling is wrong.

96 3 4-11 = 61 pages.

61 + 36 = 96 pages.

Xiaodong is right.

96-35 = 61 pages.

96 1 2+12=60 pages 61 pages.

Xiaoling is not right.

Xiaodong is right, because the number of pages I haven't read is 96-35=61 pages Xiaodong said 96*3 4-11=61 pages Xiaoling said 96*1 2+12=60 pages So Xiaodong is right.