The absolute value of b is equal to 7. Absolute value means the distance from zero. In simple terms, the positive version of the number. B could be 7 or -7, since both will be equal to 7 when you take their absolute value.
Here is the work for it I had to do it like this because I don’t have the right tools
Step 1 says to add 7 to both sides
Vertical angles are equal
so
4x + 7 = 5(x - 4)
4x + 7 = 5x - 20
5x - 4x = 7 + 20
x = 27