Предмет: Математика, автор: DarkneSs94

люди помогите кто может.

сплав меди с цинком, содержащий 80 г. цинка, сплавлен со 100 г. цинка. в результате содержание цинка в сплаве повысилось на 20%. сколько граммов меди в сплаве?

Ответы

Автор ответа: мариника

Х гр.- весь сплав

0,8х -цинк

0,8х+100=0,8х*1,2

0,8х-0,8х*1,2=-100

0,16х=100

х=625 гр.- весь сплав

625*(100-80)/100=125 гр. меди в сплаве

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