Answer: 55g + 10
1. Multiply expression before bracket, by expressions inside brackets:
3.5(10g - 2) + 17 + 20g
35g - 7 + 17 + 20g
2. Add or subtract similar expression (numbers by numbers, and variables by variables):
35g - 7 + 17 + 20g
35g + 20g - 7 + 17 =
55g + 10
Hope this helps!