2/9=80
80*9/2=360
ответ: 360
( Х - 5/18 ) : 16/27 = 1 17/64
Х - 5/18 = 16/27 • 1 17/64
16/27 • 1 17/64 = 16/27 • 81/64 = 3/4
Х - 5/18 = 3/4
Х = 5/18 + 3/4
5/18 + 3/4 = 10/36 + 27/36 = 37/36 = 1 1/36
Х = 1 1/36
R² = L²-H²=17²-8²=225 R=√225=15
V=1/3πR²H= 1/3π·15²·8=1800π
S=πR(R+L)= π·15·(15+17)=480π