Final answer:
The value of b in the simplified expression (5x-6)(x+8) is 34.
Step-by-step explanation:
To determine the value of b in the expression (5x-6)(x+8) when simplified, we need to multiply the terms in each binomial. Using the distributive property, we get:
(5x-6)(x+8) = 5x(x+8) - 6(x+8) = 5x^2 + 40x - 6x - 48 = 5x^2 + 34x - 48
So, the value of b is 34.