1.(5a²b-二分之一ab²)+(-4ba²+2ab²)
=5a^2b-1/2ab^2-4a^2b+2ab^2
=a^2b+3/2ab^2
2.(6m²+4m-3)-(2m²-4m-1)
=6M^2+4M-3-2M^2+4M+1
=4m^2+8m-2
3.(8xy-x²+y²)-3(-x²+y²+5xy
=8xy-x²+y²+3x^2-3y^2-15xy
=2x^2-2y^2-7xy
1.(5a²b-二分之一ab²)+(-4ba²+2ab²)
=5a^2b-1/2ab^2-4a^2b+2ab^2
=a^2b+3/2ab^2
2.(6m²+4m-3)-(2m²-4m-1)
=6M^2+4M-3-2M^2+4M+1
=4m^2+8m-2
3.(8xy-x²+y²)-3(-x²+y²+5xy
=8xy-x²+y²+3x^2-3y^2-15xy
=2x^2-2y^2-7xy