Question

Factorize the following quadratic polynomial by using the method of completing the square:​

Answer 1

D = b²-4ac

= 12² - 4*4*5

= 144 - 80

= 64

x = -b± √D/2a

= -12± √64/8

x = - 12+8/8. , -12-8/8

x = -2/8. , -5/2

Answer 2

Hi...


$4 {y}^{2} + 12y + 5 = 0$

$4 {y}^{2} + 12y = - 5$

$4 {y}^{2} + 12y + 36 = - 5 + 36$

$4 {y}^{2} + 12y + 36 = 31$

$2(2 {y}^{2} + 6 y+ 18) = 31$

${(2y + 9)}^{2} = \frac{31}{2}$


$2y + 9 = \sqrt{ \frac{31}{2} }$

$2y = \sqrt{ \frac{31}{2} } - 9.... - \sqrt{ \frac{31}{2} } - 9$

$2y = \frac{1}{2} (\sqrt{ \frac{31}{2} } - 9)...... \frac{1}{2} (- \sqrt{ \frac{31}{2} } - 9)$

#tq