Сколько существует трёхзначных чисел, произведение цифр которых равно 6? запиши эти числацифры в записи числа могут повторятся

123,132,114,141,222,231,213,321,312,411 вроде все

123 213 312 321 132 231 ответ: 6 чисел

Обозначим одну сторону а, вторую b тогда периметр 2а+2b = 18 площадь а * b= 20 из первого уравнения   выражаем а = (18 - 2b)/2 = 9 - b подставляем это во второе уравнение : (9 -b) b = 20                                                                 b^2 - 9b +20 =0 решаем это квадратное уравнение: b1 =5   a1 = 9 - 5 =4                                                         b2=4   a2 = 9 - 4 =5 ответ: стороны прямоугольника 5см и 4см.

Developed over the centuries a traditional complex of clothing, footwear and accessories, which was used in the russian daily and holiday items. has distinct characteristics depending on the region, gender (male and female), destination (holiday, wedding, and daily) and age (children's, girl's, a married woman, the old woman). with the general similarity in the cut and receptions russian costume jewelry has its own peculiarities. in the north, russian peasants wore, significantly different from the peasants of southern districts. in central russia wore a suit similar in nature to the north, however, in some specific areas can be seen with the features of the southern russian costume clothes [1]. a distinctive feature of russian national costume - a large amount of clothing. clothing union and swing. cap clothing worn over the head, swing had a cut from top to bottom and end to end fastens on hooks or buttons.