To solve the equation \(16 - 3(d + 4) = 9d - 8\), let's first simplify the left side.
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Distribute \(-3\) on the left: \[ 16 - 3(d + 4) = 16 - 3d - 12 \] This simplifies to: \[ 4 - 3d \]
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Now we have: \[ 4 - 3d = 9d - 8 \]
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Next, add \(3d\) to both sides: \[ 4 = 12d - 8 \]
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Now, add \(8\) to both sides: \[ 12 = 12d \]
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Finally, divide by \(12\): \[ d = 1 \]
Thus, the solution to the equation \(16 - 3(d + 4) = 9d - 8\) is \(d = 1\).
For the expression \(16 + -3(d + 4) = 9d - 8\), it simplifies to the same equation as above, leading to the same result.
Now, for the equation \(16 + + ? = 9d - 8\), if we let \(? = -3(d + 4)\), then it holds:
- \(16 + -3(d + 4) = 9d - 8\)
This equals: \[ 16 - 3(d + 4) = 9d - 8 \]
So, \(? = -3(d + 4)\) is the appropriate completion of the equation where \(d = 1\).
To conclude:
- The value of \(d\) that satisfies the original equations is \(d = 1\).
- The missing term \(?\) in your expression \(16 + + ? = 9d - 8\) is \(-3(d + 4)\).