解600 ≤ (15-10)x+(40-30)(80-x) ≤ 610要步骤
问题描述:
解600 ≤ (15-10)x+(40-30)(80-x) ≤ 610要步骤
答
600 ≤ (15-10)x+(40-30)(80-x) ≤ 610
600≤5x+800-10x≤610
600≤-5x+800≤610
-200≤-5x≤-190
38≤x≤40