Предмет: Математика, автор: Rextek

два прямоугольника имеют одинаковую площадь равную 70м2.Известно что у первого прямоугольника длина на 4 метра больше а ширина на 2 м меньше чем у второго

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Автор ответа: Аноним

S1=70; S1=a*b, a=70/b. S2=70; S2=(a-4)(b+2). Составим уравнение: (70/b-4)(b+2)=70. Решим уравнение относительно b. (70-4b)(b+2)=70b; 70b +140-4b^2-8b=70b; -4b^2-8b+140=0; -b^2-2b+35=0; b^2+2b-35=0; D= 2^2-4*(-35)=144; b1=(-2-12)/2=-14/2=-7 (не подходит, т.к. <0). b2=(-2+12)/2=10/2=5 (м)- ширина одного прямоугольника; a=70/5=14 (м) – длина одного прямоугольника. Следовательно, 14-4=10 (м) – длина другого прямоугольника, 5+2=7 (м)- ширина пдругого прямоугольника. Ответ: стороны прямоугольников – 7м и 10м, 5м и 14м.
знаю много

Автор ответа: Rextek

можешь написать как в 5 классе

Автор ответа: Аноним

Ок :)

Автор ответа: Аноним

а*в = 70 (1)

(а+4)*(в-2) = 70 (2)

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