4x+2m=3x+1
x=1-2m
3x+2m=6x+1
-3x=1-2m
x=-(1-2m)/3
∴1-2m=-(1-2m)/3
∴m=1/2
(m+2)（2m-7/5）²
=(1/2+2)(2×1/2-7/5)²
=5/2×(-2/5)²
=2/5