Use SAMDEB (Subtraction/Addition, Multiplication/Division, Exponents, Brackets, Repeat if necessary after brackets removed)

In this case

subtract 6 on both sides

divide by -3 on both sides

Multiply both sides by b^{-2} and divide by 4

Take the square root on both sides (Exponents)

Recall the fact that since the square root is also a power (of ) and hence