1.5(3a-2b)+4（2b-3a）=15a-10b+8b-12a=3a-2b2.1/3（a-2b）-1/4（3a-2b）-1/2(a-b)=a/3-2b/3-3a/4+b/2-a/2+b/2=(1/3-3/4-1/2)a+(-2/3+1/2+1/2)b=-11a/12+b/33.(x+y)a-(x-y)=ax+ay-x+y=(a-1)x+(a+1)y