来自汪和才的问题
已知a=3b,c=4a,代数式4a-9b+3c/3a-6b+c的值为()A.6B.13/5C.13D.16/7
已知a=3b,c=4a,代数式4a-9b+3c/3a-6b+c的值为()A.6B.13/5C.13D.16/7
1回答
2020-03-2409:12
已知a=3b,c=4a,代数式4a-9b+3c/3a-6b+c的值为()A.6B.13/5C.13D.16/7
已知a=3b,c=4a,代数式4a-9b+3c/3a-6b+c的值为()A.6B.13/5C.13D.16/7
依题意得:a=3b,c=4a,则:b=a/3,
则:4a-9b+3c=4a-9*(a/3)+3*4a=4a-3a+12a=13a
3a-6b+c=3a-6*(a/3)+4a=3a-2a+4a=5a
所以:(4a-9b+3c)/(3a-6b+c)=13a/5a=13/5
选B