What is 13/20 as a part to part ratio

I’m stuck on this i don’t understand.

Follow these steps using the algebra tiles to solve the equation −5x + (−2) = −2x + 4. 1. add 5 positive x-tiles to both sides and create zero pairs. 2. add 4 negative unit tiles to both sides and create zero pairs. 3. divide the unit tiles evenly among the x-tiles. x =

Find the number of liters in 12.8 gal of gasoline. round to the nearest hundredths