Câu 15:

Cho dãy số ${u_n},{v_n}$ thỏa $\mathop {\lim }\limits_{} {u_n} = 2;\,\,\mathop {\lim }\limits_{} {v_n} = 1.$Tính $\mathop {\lim }\limits_{} \left( {2{u_n} - 3{v_n}} \right).$