5*(1/2)^x:(1/2)^3+(1/2)^x*1/2=162
5*(1/2)^x*8+(1/2)^x*1/2=162
40*(1/2)^x+1/2*(1/2)^x=162
(1/2)^x=t
40t+t/2=162
81t=324t=4
(1/2)^x=4 или (1/2)^x=(1/2)^-2 x=-2
Номер 417
а) 3 5/16+1/4-2 1/16=53/16+1/4-33/16=53/16+4/16-33/16=24/16=6/4=3/2=1 1/2
б) 1/8+2 3/5+2 7/8=1/8+13/5+23/8=5/40+104/40+115/40=224/40=56/10=28/5=5 3/5
в) 6 11/12-3 1/6-1 1/4=83/12-19/6-5/4=83/12-38/12-15/12=30/12=5/2=2 1/2
г) 3 7/9-1 5/18+3 1/2=34/9-23/18+7/2=68/18-23/18+63/18=108/18=12/2=6
(1) 24 : 2 - 8 = 12 - 8 = 4 ( см ) - другая сторона.
Ответ: 4 сантиметра.