Question

plzz tell me how to complete a square
3x^2 + 6x -4 can u write it in this form? p(x-q) +r

Answer 1

re-write
3x^2 + 6x -4
as
3 ( x^2 + 2x) -4
inside the parens we have x^2 + bx
where b is the coefficent. we want to add (b/2)^2 to complete the square
here b=2, so (b/2)^2 = 1^2= 1.
But to not change the value we add 1 -1 (make sense?)
3 (x^2 +2x +1 -1) -4
if you work it out, x^2+2x+1 = (x+1)^2 so we now have
3 ( (x+1)^2 -1) -4 or multiplying by 3
3(x+1)^2 -3 -4 =
3(x+1)^2 -7