Question

mx + ny = m2 - n2 and ny + mx = 0 , Find the value of ( x + y)

Answer 1

I think it should be nx + my = 0.

so add the two equations

(mx+ny) +(nx+my) = m^2-n^2.

m(x+y)+n(x+y) = m^2-n^2

(x+y)*(m+n) = m^2-n^2

x+y =(m^2-n^2)/(m+n).

then using the identity a^2-b^2=(a+b)(a-b)

x+y = m-n.