Question

daca a si b sunt numere reale astfel incat a la a doua =10+b la a doua si a+b=5,atunci a-b este egal cu... ?

Answer 1

a+b=5=>a=5-b, inlocuind in a^2=(10+b)^2=> (5-b)^2=(10+b)^2=> 5-b=10+b=> 5-b-10-b=0=> -5-2b=0=> -2b=5=> b=-5/2, a=5-(-5/2)= 15/2 => a-b= 15/2 -(-5/2)=20/2=10