# A linear algebra solve found zero solutions, weirdly [closed]

Let `E`

, `P`

, `QA`

be points of a 3D space, let `a*QAx+b*QAy+c*QAz==d`

ensures that `QA`

is in a certain plane. Let |E P| and |E QA| be the same line. Why did my attempt to find QA found zero solutions?

```
#!/usr/bin/env python
# coding: utf-8
# In[1]:
var('a b c d')
# In[2]:
var('Ex Ey Ez')
# In[3]:
E=vector([Ex,Ey,Ez])
# In[4]:
var('Px Py Pz')
# In[5]:
P=vector([Px,Py,Pz])
# In[6]:
var('k QAx QAy QAz')
# In[7]:
QA=vector([QAx,QAy,QAz])
# In[14]:
solve([E-P==k*(E-QA), a*QAx+b*QAy+c*QAz==d], [k, QAx, QAy, QAz])
```

Ine't that a duplicate of your other question ?