Question

why we should add b/2a in completing square method?​

Answer 1

Answer:

Step-by-step explanation:

with a little inspiration from Geometry we can convert it, like this: As you can see x2 + bx can be rearranged nearly into a square ... So, by adding (b/2)2 we can complete the square. And (x+b/2)2 has x only once, which is easier to use.

Answer 2

Answer:

Step-by-step explanation:

( x + b/2)²  = x² +bx + (b/2)²

note that the last term (b/2)² is the square of half the co-efficient of x . Hence , the x² +bx lacks only the term (b/2)² 0f being the square of x +b/2

  Thus, if the square of half the co-efficient of x be added to an expression of the form x² +bx,  the result is the square of a binomial.