Solving Simultaneous Equations Fastest Way

Q) 2x + 3y = 13; 4x + 5y = 23?

Ans: Now take LHS of both the equations and cross multiply and subtract. We get 3*4-5*2 = 2. Let it be 'a'.

Now to find x neglect the x terms and cross multiply the other terms,find the difference and divide the whole term by 'a'.

i.e, x=(3*23-5*13)/a = (69-65)/2 =4/2 =2; y=(13*4-23*2)/a = (52-46)/2 =6/2 =3.