Question

：(-1/2)+3又4分之1+2.75+(-6又2分之1)(-2.4)+(-3.7)+(+4.2)+0.7+(-4.2)

Answer 1

(-1/2)+3又4分之1+2.75+(-6又2分之1)

=-1/2+3又4分之1+2.75-6又2分之1

=-(1/2+6又2分之1)+(3.25+2.75)

=-7+6

=-1

(-2.4)+(-3.7)+(+4.2)+0.7+(-4.2)

=-2.4-3.7+4.2+0.7-4.2

=-2.4-(3.7-0.7)+(4.2-4.2)

=-2.4-3+0

=-5.4