According to the question, it means: 4x+(x+1)+(x+2)+(x+3)+(x+4) =10 (x+3)+(x+4).

Solution: x =-8 is impractical.

(2) If the first four digits are all X, the last four digits are X-1,X-2, X-3, X-4,

According to the meaning of the question: 4x+(x-1)+(x-2)+(x-3)+(x-4) =10 (x-3)+(x

Solution: x = 8.

So the last four digits are 7654, so the phone number of the teacher's home is 88887654.