1 answer
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First, let's substitute the given values into the equation:
Cost = 1.50 * (2L + 2w)
Cost = 1.50 * (2 * 4 + 2 * 3)
Cost = 1.50 * (8 + 6)
Cost = 1.50 * 14
Cost = $<<1.5*14=21>>21. Answer: \boxed{21}.