3 2/5w = 17/2
First we need to convert 3 2/5 into an improper fraction:
3 2/5 = 17/5
Ok after we've done that lets write out the equation:
17/5w = 17/2
After that lets divide each side by 17/5:
(remember that dividing a fraction is equivalent to multiplying the reciprocal)
17/5w x 5/17 = 17/2 x 5/17
w = 5/2
w = 2.5