The x-y plane is where z=0. The point where the line crosses this plane has z=0.
The line is given as:
3x−3=2y+1=−2z−4
This is the symmetric form of a line. All three fractions are equal to some parameter k.
3x−3=2y+1=−2z−4=k
This gives:
x−3=3k
x=3k+3
y+1=2k
y=2k−1
z−4=−2k
z=−2k+4
On the x-y plane, z=0:
−2k+4=0
−2k=−4
k=2
Substituting k=2:
x=3(2)+3
x=6+3
x=9
y=2(2)−1
y=4−1
y=3
z=0
Therefore, the point where the line crosses the x-y plane is (9,3,0).