-0.5-(-3又4分之1)+2.75-7又2分之1等于多少?

-0.5-(-3又4分之1)+2.75-7又2分之1
=-0.5+3.25+2.75-7.5
=-8+6
=-2
-1又2分之1×7分之5-（-7分之5）×2又2分之1+（-2分之1）×5分之7
=-3/2x5/4+5/7x5/2-1/2x5/7
=5/7x(-3/2+5/2-1/2)
=5/7x1/2
=5/14