which is correct?

A. a+2=3(a−6+2)

B. a=3(a+2)

C. 3(a+2)=a−6+2

D. a+2=3(a+6+2)

5 answers

To determine which equations are correct, we can simplify each option.

A. \( a + 2 = 3(a - 6 + 2) \)

Simplifying the right side:

\[ 3(a - 6 + 2) = 3(a - 4) = 3a - 12 \]

Thus, the equation becomes:

\[ a + 2 = 3a - 12 \]

Rearranging gives:

\[ 2 + 12 = 3a - a \] \[ 14 = 2a \quad \text{or} \quad a = 7 \]

This equation is valid when \( a = 7 \).


B. \( a = 3(a + 2) \)

Simplifying the right side:

\[ a = 3a + 6 \]

Rearranging gives:

\[ a - 3a = 6 \] \[ -2a = 6 \quad \text{or} \quad a = -3 \]

This equation is also valid when \( a = -3 \).


C. \( 3(a + 2) = a - 6 + 2 \)

Simplifying both sides:

Left side:

\[ 3(a + 2) = 3a + 6 \]

Right side:

\[ a - 6 + 2 = a - 4 \]

So, we have:

\[ 3a + 6 = a - 4 \]

Rearranging gives:

\[ 3a - a = -4 - 6 \] \[ 2a = -10 \quad \text{or} \quad a = -5 \]

This equation is valid when \( a = -5 \).


D. \( a + 2 = 3(a + 6 + 2) \)

Simplifying the right side:

\[ 3(a + 6 + 2) = 3(a + 8) = 3a + 24 \]

Thus, the equation becomes:

\[ a + 2 = 3a + 24 \]

Rearranging gives:

\[ 2 - 24 = 3a - a \] \[ -22 = 2a \quad \text{or} \quad a = -11 \]

This equation is valid when \( a = -11 \).


In summary, all equations A, B, C, and D can be considered correct as they each hold true for specific values of \( a \). If the intent is to find an equation that is generally true for all \( a \), no single statement meets that criterion.

here the problem

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?

Let's denote Tony's current age as \( a \) years. According to the problem, Andrea is 6 years younger than Tony, which means:

  • Andrea's current age \( = a - 6 \)

In two years, Tony's age will be \( a + 2 \), and Andrea's age will be \( (a - 6) + 2 = a - 4 \).

The problem states that in two years, Tony will be three times as old as Andrea:

\[ a + 2 = 3(a - 4) \]

Now we can simplify this equation:

  1. Distributing the 3 on the right side: \[ a + 2 = 3a - 12 \]

  2. Rearranging the equation by moving all terms involving \( a \) to one side and constant terms to the other: \[ 2 + 12 = 3a - a \] \[ 14 = 2a \]

  3. Therefore, the equation can also be expressed as: \[ 2a = 14 \]

This equation represents the relationship between Andrea's and Tony’s current ages based on the information provided.

Thus, the linear equation you can use to find their current ages is: \[ a + 2 = 3(a - 4) \] or equivalently, \[ 2a = 14. \]

so which answer is it
A.
B.
C.
or D.?

Based on the information given and the derived equation:

\[ a + 2 = 3(a - 4) \]

You need to compare this equation to the options A, B, C, or D to find the correct one. Since the original options were not provided with specific equations, I will restate the equation we found and clarify which type of equation to look for.

If the options were something like:

A. \( a + 2 = 3(a - 6 + 2) \)

B. \( a + 4 = 3(a - 6) \)

C. \( a + 2 = 3(a - 4) \)

D. \( a + 2 = 3(a + 2 - 6) \)

Then C is the correct choice based on your original problem description and the equation we derived.

Please provide the specific equations associated with A, B, C, and D, and I'll confirm which one corresponds to the relationship accurately.