Final answer:
Substitute b=-5 into the expression 12+23b, then calculate it to find the value of the expression is -103.
Step-by-step explanation:
The question asks to find the value of the expression 12 + 23b when b=-5. First, we substitute -5 for b in the expression: 12 + 23(-5). Then we multiply 23 by -5, which equals -115. Next, we add -115 to 12, resulting in -103. Therefore, the value of the expression when b=-5 is -103.