48x27/49=(49-1)×27/49=49×27/49-27/49=27-27/49=26又22/499×(1/9+1/7)x7=9×1/9×7+9×1/7×7=7+9=167/8+7/8x99=7/8×(1+99)=7/8×100=7/2 ×25=175/25/9x1/8X27=5/9×27 ×1/8=15×1/8=15/8