(2) 50-6=44,70-4=66,90-3=87,100-9=91
(3) 70-5=65,80-4=76,100-4=96,100-9=91,52+8=60,60-8=52,43-20=23,43-2=41
(30*48)+(30*52)=1440+1560=3000
(30*48)+(30*52)=30(48+52)=30*100=3000
Ответ: