Remark
Multiply both sides of the equation by 25. Then you have an equation that you have already done probably.
Step One
Multiply both sides of the equation by 25
1 * (20 - t) = 4t - (3/5) * 25 Every part of the equation must be multiplied by 25
(20 - t) = 4t - 75/5 3*25/5 = 75/5
20 - t = 4t - 15 Add t to both sides
20 - t + t =4t + t - 15 Combine like terms
20 = 5t - 15 Add 15 to both sides
20 + 15 = 5t - 15 + 15 Combine like terms
35 = 5t Divide by 5
35/5 = 5t/5 Switch sides
t = 7 Answer