If m : n = 5 : 4 then what is the value of (m2 + n2) : (m2 − n2) ?

If m : n = 5 : 4

then what is the value of (m² + n²) : (m² − n²) ?

Put the value of m and n in the required equation,

(m² + n²) : (m² − n²)

= (5² + 4²) : (5² − 4²)

= (25 + 16 ) : (25 - 16)

= 41  : 9