(x,y) i.p. (6,5)=> 6x=5y=>y=6x/5
(3x+8y)/(5x+y)=(3x+6x/5)/(5x+6x/5)=(21x/5)/(31x/5)=21x/31x=21/31
(x²+y²)/8xy=(x²+36x²/25)/8*6x²/5=(61x²/25)/48x²/5=61x²/5*48x²=61/240
