A rectangular piece of paper, with a circumference of 90 cm and a length of 3 2 times its width, how

1) Let the width be x centimeters, please list the equation for x.

3/2x+x）×2=90

5/2x×2=90

5x=90x=18

2) Please explain why x = 18 is the solution to the listed equation and x = 20 is not.

Bring x=18 into the equation, left = (3 2 18 + 18) 2 = (27 + 18) 2 = 45 2 = 90 = right.

So x=18 is the solution of the equation.

Bring x=20 into the equation, left = (3 2 20 + 20) 2 = (30 + 20) 2 = 50 2 = 100 ≠ right.

So x=20 is not the solution of the equation.

You're counted. 2x+2*3/2x=90

x=18 Assuming x=20, then the length is 30, and the circumference of such a rectangle is 100.

1) Let the width be x centimeters, please list the equation for x.

2x＋3/2×2x=90

x=18cm

2) Please explain why x = 18 is the solution to the listed equation and x = 20 is not.

If x=20, then the length is 20 3 2 = 30cm, then the circumference is 30 2 20 2 = 100cm 90cm is obviously not in line with the topic.

Circumference of the rectangle = (length and width) 2

2x+3x=90

x=18 substitutes x=18 into the original equation left=right.

However, x=20 substitution into the original equation does not.

Knowing that the length of the rectangle is six centimeters, because the overtime width is 3 times the width, then the width is 6 3 = 2 centimeters, according to the relationship between length and width, it is easy to come out of the length of the old smile.

Then the requirement is the circumference of the rectangle, now the known condition is the length and width, then it is very easy to find the circumference, according to the calculation formula of the perimeter of the rectangle, first find the sum of the length and width is 6 + 2 and so on, and then expand the box twice to get the circumference of the rectangle, that is, 1.2 is 16 centimeters.

In the end, the width of the rectangle is 2 centimeters, and its circumference is 16 centimeters.

The first empty question is missing something, is it asking about the area, the bridge hunger then the answer is, 108, 48

If a blank question in Diminster asks what is the length of a limb, then the answer is 18,48

48 2 (3+1), =48 2 4, =6 (cm).

A: The width is 6 cm

So the answer is: 6

Solution: If the width of the rectangular paper is a centimeter, the length is (a+4) centimeters. According to the meaning of the question, 2 [a+(a+4)]=36,4a=36-8 is solved, and Bizi a=7, then the length is a+4=7+4=11, because 7 and 11 are prime numbers, which is in line with the topic.

Therefore, the area of the rectangular paper is 11 7 = 77 (square centimeters) Answer: The area of this rectangular paper is 77 square centimeters.

Let the rectangular Mengxin be x cm wide and x + 4 cm long, and the column equation, [x+(x+4)] 2=36

The solution is x = 7 cm, the wide branch is 7 cm, the length is 7 + 4 = 11 cm, and the rectangular paper area = 7 11 = 77 square centimeters.

Because it is rectangular, the circumference = 2 (long mu only + width) = 36 cm, so length + width = 18 cm, length - width = 4 cm.

So length = (18 + 4) 2 = 11 cm, and width = 18-11 = 7 cm.

Because the length is twice as wide, the length and width are a total of 3 parts, according to the formula for the circumference of the rectangle, it is (length + width) x2 48

Length + width 24,24 3 8 cm, length is 2x8 16 cm.

A: The length is 16 cm and the width is 8 cm.

The formula for the circumference of the rectangle is: (length + width)*2

Then it's 3 width * 2 = 48

The width is 8 and the length is 16

Let the width be x, then the length is 2x the circumference of the rectangle = (length + width) * 2 = (x + 2x ) * 2 = 48 to solve x = 8, the length is 8 * 2 = 16 A: The length of the rectangle is 16 cm and the width is 8 cm.

Rectangle circumference = (length + width) x2

The length is 2 times the width, that is, 3 width x 2 = 48, and the width = 48 6 = 8 cm is obtained.

Length = 8x2 = 16 cm.

According to the title, this is a rectangle, the circumference of the rectangle = (length + width) x2, let the width be a, then the length is 2a, so (2a + a) x2 = 48. The solution is a=8, so the length of the rectangle is 16 centimeters and the width is 8 centimeters, I hope my answer can help you.

Solution: Assuming that the width of the rectangle is a centimeter, then the length is 2a, 2a+2x2a=48, 6a=48, a=. The length of the rectangle is 16 cm and the width is 8 cm.

Solution: Let the width be b, 6b = 48, b = 8 cm, length = 16 cm.

It can be solved by an equation that allows the width to be x centimeters and the length to be 2x centimeters, and according to the circumference, 2(x+2x)=48

3x=24x=8, and the length is 2x=16

So the length is 16 centimeters and the width is 8 centimeters.

The greatest common divisor of 48 and 36 is 12. So the side length of the square is 12 cm.

Well, the greatest common factor for 48 and 36 is 12 by short division, and 2*2*3=12, so the side length of the square is 12 cm.

According to the topic, we know that the circumference of a rectangle is 48 cm, we first calculate the length of the length and width of the total equation is 48 2 = 24 cm, the length and width of the length is twice the width, the width is double the amount, the length is twice the amount, we have to calculate the total number of times, our second equation is 2 + 1 = 3, the third equation is 24, divided by 3 = 8, this is the length of the width, and then I can't hear that Changshu is twice the width, so our last formula is 2 8, equal to 16 centimeters, That's the length.

According to the inscription, we know: half of the circumference is 48 2 = 24 cm length + width = 24, and the length is twice as wide, so three times the width is 24 cm, so the width is 24 3 = 8 cm.

So the length is 8x2 = 16 cm.

The sum of length + width is: half of the circumference.

48 2 = 24 centimeters.

The length is twice as wide, then the length + width = 2 widths + 1 width = 3 widths is: 24 3 = 8 cm.

The length is: 8x2 = 16 cm.

The side length of the smallest square is (2+1) 2=6 (cm), which requires sheets).

The length of the trousers is 6 2 = 12 (cm), 18 4 = 72 (pieces), and the remaining 8 pieces are useless, so the circumference of the square spelled into the god is 12 4 = 48 (cm).

The sides of the square are equal in length, so a minimum of 2 rectangular pieces of paper are needed to spell out a square, the side length increases by 2, and the number required each time is: 2 8 18 32 50 72, the next time the pants are subtracted, the resulting number is 6 10 14 18 22 26, even if the number is very large, it is so much, the previous number is subtracted from the next number, and 4 is obtained, that is, the maximum number of 72 rectangles can be used, because the side length is increased by 2 each time, the Hu crack companion is: 2 4 6 8 10 12, the maximum length of the edge source is 12, and the area is 144cm.

You can go backwards and the square side length is 12, so there are 6x6x2=72 rectangles.