(4*1200)*х9600
4800*х=9600
Х=9600:4800
Х=2
-------------------------
Х*(5600:8)=21000
Х*700=21000
Х=21000:700
Х=30
-------------------------
(7300-5300)*х=72000
2000*х=72000
Х=72000÷2000
Х=36
-------------------------
Х*(4500+1500)=30000
Х*6000=30000
Х=30000÷6000
Х=5