2014 · Q23
(x + y) : (x − y) = 3 : 5 and xy = positive imply that
Elementary MathematicsAlgebra
- Ax and y are both positive
- Bx and y are both negative
- Cone of them is positive and one of them is negative
- Dno real solutions for x and y exist
Explanation
5(x + y) = 3(x − y) gives x = −4y, so xy = −4y² ≤ 0, contradicting xy positive.