The other number is -2.
Explanation:
Step 1; Assume the other number is x. So 4 times the difference between x and 1 is equal to x-10. So we formulate the equation as
4(x -1) = x - 10,
4x - 4 = x - 10,
Transferring the unknown values to the left side and keeping the known values on the right we get
4x - x = -10 + 4,
3x = -6.
x = -2.
So the other number is -2.
Step 2; To check if we got the right number we substitute it into the given equation and see if it matches.
Equation is 4(x -1) = x - 10 substituting x=-2 we get,
4(-2 -1) = -2-10, - 12 = -12. Both sides are equal so the other number is -2.