Question

Evaluate: (x+7)(x-3) - x(x 4)

Answer 1

Answer:

$(x + 7)(x - 3) - x(x4) \\ {x}^{2} - 3x + 7x - 21 - 4 {x}^{2} \\ - 3 {x}^{2} + 4x - 21 \\ \\ = {4}^{2} - 4 \times - 3 \times 21 \\ 16 + 252 \\ d = 268.$

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