3.6×2.36+3.61×6.4
=3.6×2.36+(2.36+1.25)×6.4
=3.6×2.36+2.36×6.4+1.25×6.4
=2.36×(3.6+6.4)+5/4×6.4
=2.36×10+5×1.6
=23.6+8
=31.6