Select all of the expressions that are equivalent to 4(6a + 9) - 15 - 8a

responses
24a + 36 -15 - 8a
24a + 9 - 15 - 8a
24a - 8a + 36 - 15
16a + 21
24a - 6

1 answer

Let's simplify the expression \( 4(6a + 9) - 15 - 8a \) step by step:

  1. Distribute the 4: \[ 4(6a) + 4(9) = 24a + 36 \] So, the expression becomes: \[ 24a + 36 - 15 - 8a \]

  2. Combine like terms: \[ 24a - 8a + 36 - 15 = (24a - 8a) + (36 - 15) \] This simplifies to: \[ 16a + 21 \]

Now we can compare this with the provided options:

  1. \(24a + 36 - 15 - 8a\): Simplifying gives \(16a + 21\), which is equivalent.
  2. \(24a + 9 - 15 - 8a\): Simplifying gives \(24a - 8a + 9 - 15 = 16a - 6\), which is not equivalent.
  3. \(24a - 8a + 36 - 15\): Simplifying gives \(16a + 21\), which is equivalent.
  4. \(16a + 21\): This is the same as the simplified result, so it is equivalent.
  5. \(24a - 6\): This is not equivalent.

So the expressions that are equivalent to \(4(6a + 9) - 15 - 8a\) are:

  • \(24a + 36 - 15 - 8a\)
  • \(24a - 8a + 36 - 15\)
  • \(16a + 21\)

In summary, the equivalent expressions are:

  1. \(24a + 36 - 15 - 8a\)
  2. \(24a - 8a + 36 - 15\)
  3. \(16a + 21\)