x-[40%x+5+(40%x+5)*80%]=12谁给个解题过程?

问题描述:

x-[40%x+5+(40%x+5)*80%]=12谁给个解题过程?

x-[40%x+5+(40%x+5)*80%]=12 x-0.4x-5-(0.4x+5)*0.8=12 0.6x-5-0.32x-4=12 0.28x=21 x=75