If a and B are rational numbers, we define a new operation "*" such that a ⁃ B = 2a-b, then (5 ⁃ 3) ⁃ 1=______ .

If a and B are rational numbers, we define a new operation "*" such that a ⁃ B = 2a-b, then (5 ⁃ 3) ⁃ 1=______ .

∵ define a new operation "∵", such that a ∵ B = 2a-b, ∵ (5 ∵ 3) ∵ 1, = (2 × 5-3) ∵ 1, = 7 ∵ 1, = 2 × 7-1, = 13