Question

paula si ilinca au impreuna 32 de castane. 1 pe 3 din nr. castanelor paulei reprezinta cat 1 pe 5 din nr castanelor ilincai.cate castane are fiecare fetita

Answer 1

P+I=32 ------ 1/3 din P=1/5 din I =>5P=3I ------- P+I=32=>P=32-I 5P-3I=0 5*(32-I)-3I=0 160-5I-3I=0 8I=160=>I=20 P=32-I=>P=12

Answer 2

p+i=32
p=32-i

1/3p=1/5i⇒ 32-i/3=i/5⇔ 3·5=5·3⇔15=15
160-5i/15=3i/15⇒ /·15
160-5i=3i
160=3i+5i
160=8i
i=160:8
i=20 castane

p=32-20
p=12 castane