Andrea is 6 years younger than Tony. In two years, Tony will be three times as old as Andrea. Let a be Tony’s current age. Which of these linear equations can be used to find Andrea’s and Tony’s current ages?(1 point)

Responses

a+2=3(a−6+2)
a plus 2 equals 3 left parenthesis a minus 6 plus 2 right parenthesis

a+2=3(a+6+2)
a plus 2 equals 3 left parenthesis a plus 6 plus 2 right parenthesis

3(a+2)=a−6+2
3 left parenthesis a plus 2 right parenthesis equals a minus 6 plus 2

a=3(a+2)

1 answer

Let's break down the problem step by step.

  1. Let \( a \) be Tony's current age.
  2. Since Andrea is 6 years younger than Tony, we can express Andrea's age as \( a - 6 \).
  3. In 2 years, Tony's age will be \( a + 2 \) and Andrea's age will be \( (a - 6) + 2 = a - 4 \).
  4. According to the problem, in 2 years, Tony will be three times as old as Andrea, which gives us the equation: \[ a + 2 = 3(a - 4) \]

Now, let's check which of the options corresponds with the correct equation:

  • Option 1: \( a + 2 = 3(a - 6 + 2) \)

    • This simplifies to \( a + 2 = 3(a - 4) \) (which is correct).
  • Option 2: \( a + 2 = 3(a + 6 + 2) \)

    • This is incorrect. It suggests that Andrea is older than Tony.
  • Option 3: \( 3(a + 2) = a - 6 + 2 \)

    • This is incorrect because it doesn't represent the relationship properly.
  • Option 4: \( a = 3(a + 2) \)

    • This is incorrect because it does not accurately represent the age relationship.

The correct response is that the equation that can be used is:

Option 1: \( a + 2 = 3(a - 6 + 2) \).