If a and B satisfy 3 √ a + 5 √ B = 7, what is the value range of S = 2 √ A-3 √ B?

If a and B satisfy 3 √ a + 5 √ B = 7, what is the value range of S = 2 √ A-3 √ B?

√a=(7-√b)/3
√a>=0,√b>=0
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