Answer:
b = -13/3
Explanation:
Plug in the 13/3 into the t and then try to solve it. Like this:
(13/3 - 8/3)(13/3 + b) = 0 ----> 5/3(13/3+b) = 0 ----> from here you have to distribute ----> 65/9 + b = 0 (here you have to subtract from both sides)
b = -65/9 (you could simplified) ---> b = -13/3