SAT Math · Equivalent expressions · medium
If (x-6)(x+2) = x² + bx + c for all values of x, what is the value of b - c?
If for all values of , what is the value of ?
Answer and explanation
Answer: B: 8
Expand: . So and . The question asks for , choice B. Choice A () is . Choice C () is alone. Choice D () has the wrong sign, which comes from computing or from subtracting without handling the double negative. Careful sign work is the whole challenge here, so write out with the values in parentheses.
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