Question

translate the sentence into an equation.twice the difference of a number and 9 equals 5.use the variable b for the unknown number.

Explanation:

Step1: Define the difference

The difference of $b$ and 9 is $b - 9$.

Step2: Multiply by 2

Twice this difference is $2(b - 9)$.

Step3: Set equal to 5

Equate the expression to 5.
$2(b - 9) = 5$

Answer:

$2(b - 9) = 5$