比大小,a+6=b+8,a〈〉b.a-3=b-8,a〈〉b.15+a=7+b,a〈〉b,怎么算出来

A=B+B+B+B+B+B+B+B+B+B+B+B+B+B+B A-B×3=C C+2×7+2=1 (2a+b)(a-b)=8 求a,b 3(a-b)²-7(a-b)+8(a-b)²+6(a-b),其中a-b=2.怎么写求解, 已知|a|=6,|b|=8,且|a+b|=|a-b|,求|a-b|. 已知|a|=6 |b|=8,且|a+b|= |a-b| 求|a-b| (3a-6b)/(a+b) - (5a-6b)/(a-b) - (4a-5b)/(a+b) - (7a-8b)/(a-b (3a-6b/a+b）-(5a-6b/a-b)-(4a-5b/a+b)-(7a-8b/b-a) a*b+b=a+b+21 a+a+b+b+b=6.5 b+b+a+a+a=7 如果a-2b/a+2b=3,求a+2b/a-2b+3a-6b/4a+8b （a-2b)/(a+2b)=3,求(a+2b)/(a-2b)+(3a-6b)/(4a+8b)的解, 3a^2b-{2a^2b+[9a^b-(6a^2b+4a^2)]-(3a^2b-8a^2)}=