If (x + y) : (x - y) = 4 : 1, then (x² + y²) : (x² - y²) is:

योगांतरानुपात (Componendo and Dividendo) का उपयोग करने पर: (x+y+x-y)/(x+y-x+y) = (4+1)/(4-1) => 2x/2y = 5/3 => x/y = 5/3। मान लीजिए x=5, y=3। (25+9)/(25-9) = 34/16 = 17:8।