Jika (a + b) : (a - b) = 1:5,maka (a pangkat 2 - b pangkat 2) : (a pangkat 2 +b pangkat 2)sama dengan..... a.2:3 b.5: 13. c.3 : 4 d.9:7

Eliminasi
a + b = 1
a - b = 5
______ +
2a = 6
a = 6 / 2
a = 3 ← (Nilai a)

Substitusikan (a = 3)
a + b = 1
3 + b = 1
b = 1 - 3
b = -2

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