Let's denote a variable to the number as x. Then, let's slowly decipher the verbal descriptions into algebraic expressions:
Nine times a number added to -5: 9x + ⁻5 = 9x - 5
twice the sum of nine times a number and two: 2(9x+2)
Let's subtract the first expression to the second expression:
2(9x+2) - (9x - 5)
Next, let's simplify the expression.
18x + 4 - 9x + 5
9x + 9
The final expression would be 9x + 9, or nine times a number added to nine.