Solve the following formula for $\displaystyle {b}$

$\displaystyle {y}={2}{m}{x}-{9}{b}$

$\displaystyle {b}=$ Preview Question 6  

Enter your answer as an expression.
But be careful...to enter an expression like $\displaystyle \frac{{{a}+{b}}}{{{3}+{m}}}$ you need to type (a+b)/(3+m). You need parentheses for both the numerator and denominator.