Bah I know it's simple stuff, but stuck on something.
My work:
a^2 - 5a + 3 = 0
translate 3 over
a^2 - 5a = -3
Divide b and square
a^2 - 5a + 25/4 = 13/4
But is the left side a perfect square?
Yes... You made it so...
a^2 - 5a + 25/4
= a^2 - 2 * 5/2 * a + (5/2)^2
= (a - 5/2)^2
