Question

aflati numarul stiind ca : 7pe 10 din el constitue 21, 3pe 4 din el constitue 12; 8pe 9 din el constitue 24; 3pe2 din el constitue 15

Answer 1

fie nr=,,a"
7/10 din a=21
7a/10=21
7a=21x10
7a=210
a=210:7
a=30

3a/4=12
3a=12x4
3a=48
a=48:3
a=16

8a/9=24
8a=24x9
8a=216
a=216:8
a=27

3a/2=15
3a=15x2
3a=30
a=30:3
a=10