Algebra, algebra, who’s for algebra

x²  – 3x – 4 = 0

x² – 3x + 2 = 6

(x – 3/2)² = 6

(x – 3/2) = √6   or   – (x – 3/2) = √6

x = 3/2 + √6   or   x = 3/2 – √6