Question

chloe asks david to try this number puzzle:

• pick a number
• add 2
• multiply by 3
• subtract 6

david’s output is 27.
what number did he start with?

Explanation:

Step1: Let the starting number be \( x \)

We define the variable \( x \) to represent the number David started with.

Step2: Translate the operations into an equation

First, add 2 to \( x \): \( x + 2 \). Then multiply by 3: \( 3(x + 2) \). Then subtract 6: \( 3(x + 2)-6 \). We know this equals 27, so the equation is \( 3(x + 2)-6 = 27 \).

Step3: Solve the equation

First, simplify the left - hand side:

$$
LATEXBLOCK0
$$

Then divide both sides by 3: \( x=\frac{27}{3}=9 \)

Answer:

9