Since this is a first grade equation, there is only one solution (or maybe not)
Let's solve it.
Move unknown terms to the left of the equal with changed sign and known terms to the right of the equal, with changed sign.
11x-7x = 15-25
4x = -10
Since x is multiplied by 4, divide both terms for 4
4x/4 = -10/4
x = -10/4