Question

ex 1 de la Metoda comparatiei

Answer 1

3 cr + 5 ca =117 lei
3 cr + 7 ca =159 lei

3 cr+ 7 ca = 159 lei
3 cr + 5 ca = 117 lei
______________
/ 2 ca =42 lei
1 ca = 42 : 2
1 ca = 21 lei


3 cr + 5 ×21 = 117 lei
3 cr + 105 = 117 lei
3 cr = 117- 105
3 cr = 12 lei
1 cr = 12 : 3
1 cr = 4 lei

Answer 2

cr=creion
ca=caiet
3cr+5ca=117
3cr+7ca=159
(3cr+7ca)-(3cr+5ca)=2ca
159-117=2ca
42=2ca
ca=21 (42÷2)
3cr+5ca=117
3cr+5×21=117
3cr+105=117
3cr=117-105
3cr= 12
cr=12÷3
cr=4