Question

Factorize each of the following quadratic polynomials by using the method of completing:

4x² - 12x + 5

Answer 1

4x² – 12x + 5

We have,

4x² – 12x + 5 = 4 (x² – 3x + \(\frac{5}{4}\))

= 4 [x² – 3x + (\(\frac{3}{2}\))² – (\(\frac{3}{2}\))² + \(\frac{5}{4}\))] [Therefore, adding and subtracting (\(\frac{3}{2}\))²]

= 4 [(x - \(\frac{3}{2}\))² – 1²] (Therefore, completing the square)