6x+2x^2-3x+x^2+1
=2x^2 +x^2+6x-3x+1
=3x^2+3x+1
=3×（-5）^2+3×（-5）+1=61
4x^2+3xy-x^2-9
=4x^2-x^2+3xy-9
=3x^2+3xy-9
=3×2^2+3×2×（-3）-9=-15
1/3m-3/2n-5/6n-1/6m
=1/3m-1/6m -3/2n-5/6n
=1/6m -7/3n
=1/6×6-7/3×2
=-11/3
3pq-4/5m-4pq
=3pq-4pq-4/5m
=-pq-4/5m
=-1/3×（-3/2)-4/5×5
=-7/2=-3又2分之1