Question

What is the intermediate step in the form (x + a)2 = b as a result of completing the
square for the following equation?
5x2 – 168 = -60x + 12

Answer 1

Answer:

5x2 – 168 = -60x + 12

5x*2 – 156 = -60x

-55x*2=156

55x=-78

x=-1.41818181818

also know as 18/7 or 1 4/7

Answer 2

Answer:

$(x+6)^{2}$ = 51

Step-by-step explanation:

5x2 – 168 = -60x + 12

5x2  + 60 x – 180 = 0

$x^{2}$  + 12 x – 15 = 0

$x^{2}$  + 12 x   = 15

        + 36      + 36

$x^{2}$  + 12 x  + 36  =  51

$(x+6)^{2}$ = 51

$\sqrt{(x+6)^{2} }$ = $\sqrt{51}$

x + 6 =  $\sqrt{51}$

x   = -6 ± $\sqrt{51}$