If the given solutions y⃗ 1(t)=[2e3t+6e−t3e3t+15e−t], y⃗ 2(t)=[−4e3t+2e−t−6e3t+5e−t]. form a fundamental set (i. e., linearly independent set) of solutions for the system y⃗ ′=[915−4−7]y⃗ , state the general solution of the linear homogeneous system, and if they do not, enter none in all of the answer blanks. express the general solution as the product y⃗ (t)=ψ(t)c⃗ , where ψ(t) is a square matrix whose columns are the solutions forming the fundamental set and c⃗ is a column vector of arbitrary constants.