Step-by-step explanation:
let's simply do the multiplications and then compare with the original.
(x-m)² + n
right ?
or is it
let's go for the first.
x² - 2mx + m² + n = x² - 3x
-2mx + m² + n = -3x
fun there we see two things :
-2m = -3
m = 3/2
and
m² + n = 0
(3/2)² = -n
9/4 = -n
n = -9/4
so our transformed expression looks like
(x - 3/2)² - 9/4