Question

Daca a+(b+5)=90,aflati,a+b;
Daca(x+y)+z=100 si y+z=60,aflati x

Answer 1

Stim ca adunarea e asociativa. Deci (a+b)+c=a+(b+c).
Adica (x+y)+z=x+(y+z)
x+(y+z)=100 >> x+60=100 >> x=100 - 60 >> x=40

Answer 2

⇒x+(y+z)=100
⇒x+60=100
⇒x=100-60
⇒x=40