Question

determine the value that makes the equation true.
-9 - b = 3.5

Explanation:

Step1: Isolate the term with $b$

Add 9 to both sides:
$-b = 3.5 + 9$

Step2: Calculate the right-hand side

$3.5 + 9 = 12.5$, so:
$-b = 12.5$

Step3: Solve for $b$

Multiply both sides by $-1$:
$b = -12.5$

Answer:

$b = -12.5$