Respuesta :

Answer:

b =±2

Step-by-step explanation:

2b^2 + 4 =12

Subtract 4 from each side

2b^2 +4-4=12-4

2b^2 =8

Divide by 2 on each side

2b^2 /2 =8/2

b^2 =4

Take the square root on each side

sqrt(b^2) = ± sqrt(4)

b =±2