Question

18−3(1d+5)
=
3d−12

d
=

Answer 1

To solve the equation \( 18 - 3(1d + 5) = 3d - 12 \), we'll start by expanding and simplifying the left side:

1. Distribute \(-3\) into the parentheses:
\[
18 - 3(1d) - 3(5) = 18 - 3d - 15
\]

2. Combine like terms on the left side:
\[
18 - 15 - 3d = 3 - 3d
\]

So the equation now reads:
\[
3 - 3d = 3d - 12
\]

Next, we can rearrange the equation to isolate \(d\):
1. Add \(3d\) to both sides:
\[
3 = 3d + 3d - 12
\]
Which simplifies to:
\[
3 = 6d - 12
\]

2. Add \(12\) to both sides:
\[
3 + 12 = 6d
\]
Simplifying gives:
\[
15 = 6d
\]

3. Divide both sides by \(6\):
\[
d = \frac{15}{6} = \frac{5}{2} = 2.5
\]

So the final answer is:
\[
d = 2.5
\]