-2.27 + 9.1w + 1.3w = -3.4w - 17.45
First, combine like terms
-2.27 + (9.1w + 1.3w) = -3.4w - 17.45
-2.27 + 10.4w = -3.4w - 17.45
Add 2.27 to both sides and 3.4w to both sides to isolate the w.
-2.27 (+2.27) + 10.4w (+3.4w) = -3.4w (+3.4w) - 17.45 (+2.27)
10.4w + 3.4w = -17.45 + 2.27
Simplify
13.8w = -15.18
Isolate the w. Divide 13.8 from both sides
13.8w/13.8 = -15.18/13.8
w = -15.18/13.8
w = -1.1
-1.1 should be your answer
hope this helps