-5^2x(3/4)+25x(1/2)-25x(1/4)=

问题描述:

-5^2x(3/4)+25x(1/2)-25x(1/4)=

-5^2x(3/4)+25x(1/2)-25x(1/4)
=-25x3/4+25x1/2-25x1/4
=25x(1/2-3/4-1/4)
=25x(-1/2)
=-25/2