Đặt \(x/3=y/5 =k => x= 3k,y = 5k\)
\(A= 5.(3k )^2 . 3.(5k)^2 / 10(3x)^2- 3(5k)^2 \)
\(= 45k^2 + 75k^2 / 90k^2 - 75k^2 \)
\(= 120k^2/ 15k^2\)
\(= 120/15\)
Đặt x/3=y/5=k=>x=3k,y=5kx/3=y/5=k=>x=3k,y=5k
A=5.(3k)2.3.(5k)2/10(3x)2−3(5k)2A=5.(3k)2.3.(5k)2/10(3x)2−3(5k)2
=45k2+75k2/90k2−75k2=45k2+75k2/90k2−75k2
=120k2/15k2=120k2/15k2
=120/15