2(3x-5)+5x
=6x-10+5x
=11x-10
-2n-(3n-1)
=-2n-3n+1
=-5n+1
4a-2(a-3b)+3(b-a）
=4a-2a+6b+3b-3a
=-a+9b
-（-x^)+2y^-1/2(-X^+4Y^)
=x^+2y^+1/2x^-2y^
=3/2x^