A)….+12×….=352B)2x²-12x+8=0​

A) 112 + 12 × 20=352

B)2x²-12x+8=0​

<=> x²-6x+4 = 0

<=> x²-6x+9+4-9 = 0

<=> (x-3)²+4-9 = 0

<=> (x-3)²= -4+9

<=> (x-3)²= 5

<=> (x-3) = ±√5

x-3 = √5 atau x-3 = -√5

x= 3+√5 atau x= 3-√5