Chapter 9 - Quadratic Functions and Equations - 9-3 Solving Quadratic Equations - Practice and Problem-Solving Exercises - Page 551: 22

$$b = .5$$

First you divide by 64 on both sides $$b^2 = 0.25$$ Then you find the square root of both sides $$b = .5$$ That is your final answer since the variable is alone now. Remember you always have to put the plus or minus sign ($\pm$) because any number under the square root that is above $0$ has $2$ has answers.