What ypu need to do here is just isolate b:
So first you have to move like terms to the same side of the equation and combine them.
In order to do that , you can add 25 to both sides of the equation to move 25 to the other side:
10b -3b -25 +25 = 4b -1 +25
10b -3b = 4b + 24
Then subtract 4b in both sides of the equation:
10b -3b -4b =24
Now just combine like terms :
3b = 24
And divide both sides of the equatoon by 3
3/3b = 24/3
b = 8
Thats the awnser : b = 8
I hope you understood my brief explanation