5×5/8-3×5/8=(5-3)×5/8= 2 ×5/8=1.25
是(5-3)×5/8=2×5/8=5/4
5×5/8-3×5/8=5/8×(5-3)=5/8×2=1又1/4
5×5/8一3X5/8=5/8x(5一3)=5/8Ⅹ2二5/4
5️×5/8-3×5/8=(5-3)×5/8=5/4