Question

If (x:y) = 2:1, then (x2 - y2) : (x2 + y2) is
a) 3:5
b) 5:3
c)1:3
d) 3:1​

Answer 1

option A) is the right answer

$x = 2 \\ y = 1 \\ 2 {}^{2} - {1}^{2} = 4 - 1 = 3 \\ {2}^{2} + {1}^{2} = 4 + 1 = 5$

I hope this will surely help u mate

Answer 2

Answer:

Right answer : a) 3:5

x:y =2:1

squaring both sides,

x2 : y2 = 4 :1

Using compodendo and dividendo,

x2 + y2 = 4+1

x2 - y2 = 4-1

Using invertendo,

(x2 - y2) : (x2 + y2) = 3:5