Question

如果m+n=2又3分之1,m-n=3又2分之1,则4(n-m)=( ).2-7分之3m-7分之3n=( ).

Answer 1

4(n-m)

=-4(m-n)

=-4*(3+1/2)

=-12-2

=-14

2-3m/7-3n/7

=2-(3/7)(m+n)

=2-(3/7)*(7/3)

=2-1

=1