4b + 5 = 1 + 5b
subtract 5 :
4b + 5 - 5 = 1 + 5b - 5
simplify :
4b = 5b - 4
subtract 5b :
4b - 5b = 5b - 4 - 5b
-b = -4
divide by -1 :
-b/-1 = -4/-1
Answer : b = 4
I hope this helps
