已知2a=3b 求分式3a^2+5ab+b^2分之2a^2-ab+3b^2的值

问题描述:

已知2a=3b 求分式3a^2+5ab+b^2分之2a^2-ab+3b^2的值

∵2a=3b,
∴a=3b/2
(2a^2-ab+3b^2)/(3a^2+5ab+b^2)
=[2*(3b/2)²-(3b/2)b+3b²]/[3(3b/2)²+5(3b/2)b+b²]
=6b²/(61/4b²)
=24/61