1.х - 20 = 40 х 20
х = (40х20)+20
х = 820
820 - 20 = 800
2. 15 + х = 800/ 20
15 + х = 40
х = 40 - 15
х = 25
15 + 25 = 40
1.х - 20 = 40 х 20
х = (40х20)+20
х = 820
820 - 20 = 800
2. 15 + х = 800/ 20
15 + х = 40
х = 40 - 15
х = 25
15 + 25 = 40