Let's solve this problem step by step.
28=8b+13b-35
Step 1: Bring 35 to 28.
+35 +35
63=8b+13b
Step 2: Add 8b and 13b.
63=21b
Step 3: Divide both sides by 21.
63/21=21b/21
So, the answer for this problem is 3=b.
