Heidi is \(\frac{1}{5}\) as old as her mother, and her mother is 45.<br><br>&bull; Heidi's age this year = \( \frac{1}{5} \times 45 = 9 \) years old<br>&bull; Last year, Heidi (Hannah) was 9 &minus; 1 = 8 years old<br><br>Final Answer: 8