Math Chapter Wise Ordinary And Partial Differential Equations, Integral Equations And Calculus Of Variations English MCQ UP PCS (Pre) 2006 Q.The differential equation: (ay2 + x + x8) dx – (y8 –y+bxy) dy = 0 is exact if: Aa=1, b=3 Ba=1, b=2 C2a+b=0 Da–b=0 Show answer Correct answer: 2a+b=0