You can
put this solution on YOUR website!You're on the right track, but you forgot to include the portion "is subtracted from 10 times the unknown number". So the equation should be

Distribute.

Combine like terms on the left side.

Add

to both sides.

Subtract

from both sides.

Combine like terms on the left side.

Combine like terms on the right side.

Divide both sides by

to isolate

.

Reduce.
----------------------------------------------------------------------
Answer:
So the answer is

which means that the unknown number is -19.