Предмет: Алгебра, автор: ироапо

ширина прямоугольника на 3 см меньше его длины. Найдите ширину прямоугольника если его площадь ровна 130 см в квадрате

Ответы

Автор ответа: stalin777

т.к прямоугольник значит площадь равна длинна*ширина
т.к площадь известна, то получим уравнение.
х-ширина
х+3 длина
130=х*(х+3)
130=х²+3х
х²+3х-130=0
дискриминант= 9+520=529
корень дискриминанта=23
х=(-3+23)/2
х=10
х2=(-3-23)/2
х2=-13(не подходит)
по этому ширина 10
Ответ:10

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