100x＋10×2x+(x+5)－2x﹦243100x+20x+x+5-2x=243119x=243-5119x=238x=21500x﹦1200(9－x)1500x=10800-1200x1500x+1200x=108002700x=10800x=4如果本题有什么不明白可以追问,如果满意请点击“选为满意答案”...