The first step for deriving the quadratic formula from the quadratic equation, 0 = ax2 + bx + c, is shown.Step 1: –c = ax2 + bx

To get from 0 = ax² + bx + c to −c = ax² + bx, subtract c from both sides. This uses the subtraction property of equality, which keeps the two sides equal when the same value is subtracted from each. The correct choice is “subtraction property of equality.”

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