已知a-b/b=1/2求3a^2-5ab+2b^2/2a^2+3ab-5b^2的值
发布网友
发布时间：2024-09-29 18:07
共2个回答
热心网友
时间：2024-10-23 04:35
a-b=b/2
a=3b/2
(3a^2-5ab+2b^2)/(2a^2+3ab-5b^2)
=(a-b)(3a-2b)/[ (a-b)(2a+5b) ]
=(3a-2b)/(2a+5b)
代入a=3b/2
（5b/2）/8b
=5/16
热心网友
时间：2024-10-23 04:35
a-b=b/2
所以
(3a^2-5ab+2b^2)/(2a^2+3ab-5b^2)
=(a-b)(3a-2b)/[ (a-b)(2a+5b) ]
=(3a-2b)/(2a+5b)
=(3a-3b+b)/(2a-2b+7b)
=(5b/2)/(8b)
=(5/2)/8
=5/16
