If s times x is equal to 2 minus x squared and t times x is equal to 3 x , which value is equivalent to open paren s circ t close paren times negative 7 ?

First evaluate t(-7) = 3(-7) = -21. Then apply s: s(-21) = 2 - (-21)² = 2 - 441 = -439, so the equivalent value is negative 439.

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