证明(x+1)(X+3)(x+5)(x+7)+15=(X"+8x)"+22(x"+8x)+120

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证明(x+1)(X+3)(x+5)(x+7)+15=(X

证明(x+1)(X+3)(x+5)(x+7)+15=(X"+8x)"+22(x"+8x)+120
证明(x+1)(X+3)(x+5)(x+7)+15=(X"+8x)"+22(x"+8x)+120

证明(x+1)(X+3)(x+5)(x+7)+15=(X"+8x)"+22(x"+8x)+120
证明:
(x+1)(x+3)(x+5)(x+7)+15
=[(x+1)(x+7)]*[(x+3)(x+5)]+15
=[(x^2+8x)+7)]*[(x^2+8x)+15)]+15
=(x^2+8x)^2+15(x^2+8x)+7(x^2+8x)+105+15
=(x^2+8x)^2+22(x^2+8x)+120

(x+1)(X+3)(x+5)(x+7)+15
=(x+1)(x+7)(x+5)(x+3)+15
=(X"+8x+7)(X"+8x+15)
=(X"+8x)"+22(x"+8x)+105+15
=(X"+8x)"+22(x"+8x)+120