3*2*2*5=60
....................
Х=2/5 : 4/15
x=2/3
ответ 2/3
длина окружности = пиД = 72 *3,14= 226,08 см
пиД = 3,14 * 0,88 см = 2,76 см
пиД = 3,14 * 250км = 785 км
а) <span>5d=-85,6-3d</span>
8d+85.6=0
d=-85.6/8
d=-10.7
б) (5b)/6-(5b+1)/9=(1b)/2+1//3
(5//6)b-(5*b/9+1/9)-b/2-(1//3)=0
(5//6)b-((5//9)b+(1//9))-b/2-(1//3)=0
(5//18)b-(1//9)-b/2-(1//3)=0
-(2//9)b-(1//9)-(1//3)=0
-(2//9)b-(4//9)=0
b=(4//9)/(-(2//9))
b=-2
// - черта дроби