54 • × +96 = 204
780 ÷ (×-7)=78

54 * x + 96 = 20454 * x = 204-9654 * x = 108x = 108 / 54 x = 2.Ответ: 2. 780 / (x - 7) = 78x - 7 = 780 / 78x - 7 = 10x = 10 + 7x = 17,Ответ:17.

54х+96=20454х=204-9654х=108х=108:54х=2780:(х-7)=78х-7=780:78х-7=10х=10+7х=17