Question

De ziua pamantului, elevii au plantat 405 arbori ( stejari, brazi, castani ). Stiind ca 313 nu erau castani, iar 234 nu erau brazi, afla cati brazi, cati stajari si cati castani au platant copii?

Answer 1

s-stejari
b-brazi
c-castani
s+b+c=405
s+b=313 deci
c=405-313=92  
92 castani
s+b+c=405
s+c=234  deci
 b=405-234=171    
171 brazi

s+c+b=405
s+92+171=405
s+263=405
s=405-263
s=142
142 stejari




Sper ca te-am ajutat!

Answer 2

S=stejari
B=brazi
C=castani
s+b+c=405
s+b=313
s+c=234
313+c=405
c=405-313
c=92

s+92=234
s=234-92
s=142


142+b=313
b=313-142
b=171

Verificare:142+171+92=405