3a+2b+5=10.8,则6a+4b-5=______.
3a+2b+5=10.8,则6a+4b-5=______.
若a:3=b:4=c:5,且a+b-c=6,则a=______,b=______,c=______.
若3a+2b=4,2a-b=5,则5a+b=______.
若a-2b=3,则2a-4b-5=______.
若a+2b-3c=4,5a-6b+7c=8,则9a+2b-5c=______.
若a+b=3,ab=-2,则(4a-5b-3ab)-(3a-6b+ab)=______.
如果4A=5B,那么A:B=______:______,A和B成______比例.
已知a:b=3:5,b:c=6:7,则a:b:c=______.
已知A=a2-ab,B=ab+b2,则A+B=______,A-B=______,3A-2B=______.
已知 3a-4(b-1)=6,则6a-8b+5=______.
规定a﹡b=5a+2b-1,则(-4)﹡6的值为______.
5A=4B(A、B不等于0).A:B=______:______.