Question

urgent ex 11 și 12 dau coroniță plssss​

Answer 1

11

15+12v=69

5c+7v=29=> 5c=29-7v

si inlocuim in prima relatie

3(29-7v) + 12v=69

87-21v+12v=69

-9v=-18

v=2lei

5c=29-7v

5c=29-7*2

5c=29-14

5c=15

c=3lei

asadar un kg de cartofi costa 3 lei si un kg e varza costa 2 lei

12. 3c+5p=2300=> 3c=2300-5p =>c=(2300-5p)/3

     4c+2p=1200

4* (2300-5p)/3 +2p=1200

4(2300-5p) +6p=3600

9200-20p+6p=3600

-14p=-5600

p=400

c=(2300-5*400)/3

c=(2300-2000)/3

c=300/3

c=100

asadar 1c+1p=100+400=500g