#### Answer

Two perpendicular lines can share the same y-intercept as long as their slopes are negative reciprocals of each other (their product is $-1$).

#### Work Step by Step

RECALL:
Two lines are perpendicular to each other if their slopes are negative reciprocals of each other (their product is $-1$).
Thus, two lines are perpendicular to each other, regardless of their y-intercepts, as long as their slopes are negative reciprocals of each other.
Example:
The line $y=-x+3$ has a slope of $-1$.
The line $y-x=3$ has a slope of $1$.
Since their slopes are negative reciprocals of each other, then these two lines are perpendicular to each other.
Note that the two lines have the same y-intercept.