Question

Периметр прямоугольника 42см.Какова длина и ширина прямоугольника,если длина в 2 раза больше,чем его ширина? Если можно решение без иксов и игреков.Пожалуйста.

Answer 1

Р = 2(а + в) = 2а + 2в

Пусть ширина   в = х, тогда

длина   а= 2х

Подставим в формулу периметра значения "а"  и  "в" и решим:

42 = 2 * 2х + 2х

42 = 4х + 2х

42 = 6х

х = 42/6

х= 7 ,   т.е.  в = 7

а = 2х = 2 *7 = 14

Ответ:  а = 14;  в = 7

Answer 2

Problem Analysis

We are given that the perimeter of a rectangle is 42 cm, and the length is twice the width. We need to find the length and width of the rectangle.

Solution

Let's assume the width of the rectangle is x cm. Since the length is twice the width, the length would be 2x cm.

The perimeter of a rectangle is given by the formula: P = 2(l + w), where P is the perimeter, l is the length, and w is the width.

Substituting the values, we have: 42 = 2(2x + x).

Simplifying the equation, we get: 42 = 2(3x).

Dividing both sides by 2, we have: 21 = 3x.

Dividing both sides by 3, we get: 7 = x.

Therefore, the width of the rectangle is 7 cm, and the length is twice the width, which is 14 cm.

So, the length of the rectangle is 14 cm and the width is 7 cm.

Answer

The length of the rectangle is 14 cm and the width is 7 cm.