CBSE Class 10 Answered

2(ax - by) + (a + 4b) =0
2(bx + ay) + (b - 4a) =0
The above equations can be written as:
2ax – 2by + (a + 4b) = 0
2bx + 2ay + (b – 4a) = 0
using cross multiplication method as,

                x                                        y                                1
– 2b                        a + 4b                                2a                           – 2b      
   2a                        b – 4a                                2b                              2a