Question

Eliana began her pizza delivering through with 1/2 of a tank of gas in a car. When she made it back to the pizzeria, 1/10 of a tank of gas was left. how much gas did Eliana use

Answer 1

$\frac{1}{2}-\frac{1}{10}=\frac{5}{10}-\frac{1}{10}=\frac{5-1}{10}=\frac{4}{10}=\frac{2}{5}$

Asnwer: Eliana used 2/5 of a tank of gas