If (3x+5y)(3x–5y)=73, find x:y.
23:6
25:6
19:7
6:25
We have, (3x+5y)(3x–5y)=73 Applying componendo and dividendo [(3x+5y)+(3x–5y)][(3x+5y)–(3x–5y)]=(7+3)(7–3) Or, 6x10y=104 Or, xy=(10×10)(4×6)=10024=256 Hence, x:y = 25:6
If (3x + 5y)/(3x – 5y) = 7/3, find x:y.