Complete the square in the quadratic function f given by fx

Complete the square in the quadratic function f given by
f(x) = 2x² - 6x + 4

Solution

f(x) = 2(x² - 3x) + 4 : factor 2 out in the first two terms
= 2(x² - 3x + (-3/2)² - (-3/2)²) + 4 : add and subtract (-3/2)²
= 2(x - 3/2))² + 17/2 : complete square and group like terms