Question

For which value of p does the pair of equation has unique solution 2x+y=5,px+2y=8

Answer 1

The given equations can be rewritten as:

1) 2x+y-5=0                      and;  2) px+2y-8=0

Here;

a1=2      b1=1       c1=-5                                            

a2=p     b2=2     c2=-8

So, for one unique solution (intersecting lines):

⇒a1/a2≠b1/b2  

⇒ 2/p≠1/2                                        

⇒p≠4

So, for every value of p except 4, the given pair of liner equations will have a unique solution.

P.S. Yes, that is how it is done! No single answer.

Happy to help.