1)9-5=4
2)4*9=36
3)36-9=27
Ответ:((9-5)*9)-9=27
2х - 16 = 20
2х = 20 + 18
2х = 36
х = 18
А) 1/6 = 5/30 = 20/120; 1/5 = 6/30 = 24/120
k = 21/120 = 7/40; 22/120 = 11/60; 23/120
б) 3/7 = 12/28; 4/7 = 16/28
k = 13/28; 14/28 = 1/2; 15/28
Принялось 387/450=129/150=43/50=0,86