1
You can verify by plugging the number 13 into the equation and following the order of operations.
17
x(3+2)
+ 13 =98.
17x(5)
+13=98
85+13
=98
2
You can use algebra:
17x(3+2)+b=98
17x5+b=98
85+b=98
-85 -85
b=13