2017 · Q28
What is the value of u equations 3 (2u + v) = 7uv, in the system of 3 (u + 3v) = 11 uv ?
Elementary MathematicsAlgebra
- A0
- B1/4
- C1/2
- D1
Explanation
Divide both equations by uv: 3(2/v+1/u) = 7 and 3(1/v+3/u) = 11. With A = 1/u and B = 1/v: 6B+3A = 7 and 3B+9A = 11. Doubling the second equation and subtracting the first gives 15A = 15, so A = 1 and u = 1. Hence option (D) 1.