Triangle abc is translated 6 units up and 3 units left to create triangle a'b'c'. is vertex a us at (-1,2) and vertex b is at (1,5) what is vertex b' at.?

You're simply asking where point 'B' winds up after the translation,
so we don't care about triangles or about point-'A'.  None of that
is relevant to this particular question.

--  'B' started out at  (1, 5) .

-- Translating 6 units up makes the y-coordinate bigger by  6 .

-- Translating 3 units to the left makes the x-coordinate less by  3 .

-- So point-'B' ends up at  (1-3,  5+6)  =  (-2, 11) .

Fgfbekbkdbe i appreciate it very much