х * 300 =1500 2700 : х=9 х : 80 = 800

х * 300 = 1500х = 1500 : 300х = 5 _______5 * 300 = 15002700 : х = 9х = 2700:9х = 300 _______2700 : 300 = 9 х : 80 = 800х = 800 * 80х = 64 000_________64 000: 80 = 800