To find the value of \( x \) where the two lines intersect, we can set the equations equal to each other since both are equal to \( y \):
- \( y = 2x + 3 \)
- \( y = x - 7 \)
Setting the two equations equal to each other gives:
\[ 2x + 3 = x - 7 \]
Now, we will solve for \( x \).
- Subtract \( x \) from both sides:
\[ 2x - x + 3 = -7 \]
This simplifies to:
\[ x + 3 = -7 \]
- Next, subtract 3 from both sides:
\[ x = -7 - 3 \]
This simplifies to:
\[ x = -10 \]
Thus, the value of \( x \) when the two lines intersect is
\[ \boxed{-10} \]