Szczegółowe wyjaśnienie:
1. 2x2 +2×3= 10 cm
2. 2x12+2×28= 80km
3. 100 = 2X+2×31 100=2X+62 -2X= 62-100 -2X=- 38 /:-2 x = 19mm
bo 2x19+2×31= 38+62=100
4. 100= 2X+ 2x45 100= 2X+ 90 - 2X=90- 100
-2x=-10 /-2 x= 5 bo
100= 2x45+2×5
5. 7m= 700cm
2x40 cm+2×700cm = 80+1400=1480cm = 14m 80 cm