解不等式:(x-4)的平方-(4-x)(8-x)≥12

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解不等式:(x-4)的平方-(4-x)(8-x)≥12解不等式:(x-4)的平方-(4-x)(8-x)≥12解不等式:(x-4)的平方-(4-x)(8-x)≥12(x-4)^2-(4-x)(8-x)≥

解不等式:(x-4)的平方-(4-x)(8-x)≥12
解不等式:(x-4)的平方-(4-x)(8-x)≥12

解不等式:(x-4)的平方-(4-x)(8-x)≥12
(x-4)^2-(4-x)(8-x)≥12
x^2-8x+16+(x-4)(8-x)≥12
x^2-8x+16+12x-32-x^2≥12
4x-16≥12
4x≥28
x≥7

(x-4)的平方-(4-x)(8-x)≥12,
x²-8x+16-x²+12x-32≥12,4x≥28,x≥7

化简得4x-16≥12
所以:x≥7

(x-4)^2-(4-x)(8-x)≥12
x^2-8x+16-(x-4)(x-8)≥12
x^2-8x+16-x^2+12x-32≥12
4x-16≥12
4x≥28
x≥7

 (x-4)^2-(4-x)(8-x)≥12

即   ( 4-x)^2-(4-x)(8-x)≥12

∴     (4-x)(4-x-8+x) ≥12

         (4-x)(-4) ≥12

         4-x ≤-3

         x≥7