(89+90+88+90+85+96+90+87+90+88+88+90+88+86+87+88+86)÷20=?

问题描述:

(89+90+88+90+85+96+90+87+90+88+88+90+88+86+87+88+86)÷20=?

(89+90+88+90+85+96+90+87+90+88+88+90+88+86+87+88+86)÷20=75.3

=[(85+86+87+88+89+90)+(86+87+88+)+(3*88+4*90+96)]÷20
=(525+261+284+360+96)÷20
=(1050+350+360)÷20
=1710÷20
=171/2