a = sqrt(b + 6) The first thing you need to do is square both sides
a^2 = b+ 6 Now it requires that you only subtract 6 from both sides.
a^2 - 6 = b
b = a^2 - 6
To get the square root sign, when you are writing your question, click on the Ω symbol, which gets you to the square root symbol.√ There's your square root sign under mathematical symbols.
