|x-4|+|x+3|>5,
问题描述:
|x-4|+|x+3|>5,
答
当x ≥ 4 时,|x-4|+|x+3|>5 ==> (x-4)+(x+3)>5 ==> 2x>6 ==> x>3 所以x ≥ 4 当-3 ≤x≤4时,|x-4|+|x+3|>5 ==> -(x-4)+(x+3)>5 ==> 7 > 5 恒成立 所以-3 ≤x≤4.当x≤ -3 时,|x-4|+|x+3|>5 ==> -(x-4)-(x+3)>5 ==> x-4+x+3 2x x