Question

1)Fie a si b doua numere reale direct proportionale cu 2 si 5. Calculati 5a-b, stiind ca 3a+b=44.
2)Aratati ca numarul a=(3√2-2√3)(3√3+2√3)-√72-(3-√2)²

Answer 1

{a;b}≈{2;5}
a/2=b/5⇒k
a=2k
b=5k
2k ×3+5k=44
6k+5k=44
11k=44
k=4
a=2×4=8
b=5×4=20
3×8+20=24+20=44