Solve 5/7∛(-343) -1/4 ∛32 + ½ ∛108

Question

The answer given is: 5/7(-7) - 1/4(2)∛4 + 1/2(3)∛4 = ∛4 - 5 and I cannot figure out where/how the -5 came from.

Answer 1

Solve 5/7∛(-343) -1/4 ∛32 + ½ ∛108

 ∛(-343) = -7, ∛32 = 8∛4, ∛108 = 3∛4

5/7∛(-343) -1/4 ∛32 + ½ ∛108 = (5/7)*(-7)) – ¼(2∛4) + ½(3∛4)

5/7∛(-343) -1/4 ∛32 + ½ ∛108 = -5 + (-2/4 +  (3/2)) ∛4

5/7∛(-343) -1/4 ∛32 + ½ ∛108 = -5 + (-1/2 + 3/2) ∛4

5/7∛(-343) -1/4 ∛32 + ½ ∛108 = -5 + (1) ∛4

5/7∛(-343) -1/4 ∛32 + ½ ∛108 = -5 +  ∛4