Question

Fifteen is three times the difference between three times a number, n, and four.

Answer 1

Translating Words into Equations

We can translate word equations into number equations by recognizing key words as operations:

• Three times = multiply by 3
• Difference = subtract
• Is = equals

Solving the Question

We're given:

• Fifteen is three times the difference between three times a number, n, and four.

Divide the sentence into parts:

• [Fifteen] [is] [three times the difference between three times a number, n, and four]

Translate into numbers and operations:

• 15 = [three times the difference between three times a number, n, and four]

• 15 = 3 × [difference between three times a number, n, and four]
• 15 = 3 × (3n - 4)

Isolate n:

15 = 3 × (3n - 4)

15 = 9n - 12

27 = 9n

n = 3

Answer

15 = 3 × (3n - 4)

n = 3