Jika (a + b) : (a - b) = 1 : 5, maka (a2- b2) : (a2 + b2) sama dengan?

(a+b) : (a-b) = 1 : 5
Maka :
a + b = 1
a = 1 - b
_________

a - b = 5
1 - b - b = 5
-2b = 5-1
b = 4/-2
b = -2.

a + b = 1
a - 2 = 1
a = 1+2
a = 3

Jadi,
(a²-b²) : (a²+b²) = (3²-(-2)²) : (3²+(-2²))
= (9-4) : (9+4)
= 5 : 13