7.5*13+31*2.5咋简算
问题描述:
7.5*13+31*2.5咋简算
答
7.5x13+31x2.5=2.5x3x13+31x2.5=2.5x(39+31)=25x7=175
答
7.5*13+31*2.5
=(2.5*3)*13+31*2.5
=2.5*(3*13+31)
=2.5*70
=175