Resolva as equações: a) 7 ???? − 5 = 3 ???? + 1 b) 3 ???? − 2 = 4 −???? + 3 c) 2 ???? + 1 − ???? − 1 = 0 d) 5 ???? + 1 − 3 ???? + 2 = 0 e) 13 + 4 2???? − 1 = 5 ???? + 2 f) 4 ???? + 5 + 3 ???? + 5 = 21 g) 2 ???? + 5 − 3 5 − ???? = 10 h) 8 ???? − 1 = 8 − 4 2???? − 3