450*240-1200*45-4500*12+5
450 * 240 - 1200 * 45 -4500 * 12 + 5 = 45(10*240 - 1200 - 100*12) + 5 =
45( 2400-1200-1200) +5= 45 * 0 + 5 = 5
450*240-1200*45-4500*12+5=108000-54000-54000+5=108000-108000+5=0+5=5