Given:
a.) Shelagh describes her age as 17 1/2 years old
b.) Luna is 9 1/12 years old
Let's determine the difference in their age
.
Step 1: Let's convert them into improper fractions.
![\text{ 17 }(1)/(2)\text{ = }\frac{\text{ (17 x 2) + 1}}{2}\text{ = }\frac{34\text{ + 1}}{2}\text{ = }(35)/(2)](https://img.qammunity.org/2023/formulas/mathematics/college/izjubko66m4ih62d0vqy1xtevhvnqx0d1i.png)
![\text{ 9 }(1)/(12)\text{ = }\frac{(9\text{ x 12) + 1}}{12}=\frac{108\text{ + 1}}{12}\text{ = }(109)/(12)](https://img.qammunity.org/2023/formulas/mathematics/college/3t1vztc6jp9njnmbskirr0k50k989475g9.png)
Step 2: Let's make them into similar fractions. (Fractions with the same denominator.)
The LCM of 2 and 12 is 12. Let's transform the two fractions into one with a denominator of 12.
![\text{ }(35)/(2)\text{ = }\frac{35\text{ x 6}}{2\text{ x 6}}\text{ = }(210)/(12)](https://img.qammunity.org/2023/formulas/mathematics/college/wiygwg08ufug6jc04jiof1pjagxr324cu6.png)
Step 3: Proceed to subtract the two numbers.
![\text{ 17 }(1)/(2)\text{ - 9 }(1)/(12)\text{ = }(210)/(12)\text{ - }(109)/(12)](https://img.qammunity.org/2023/formulas/mathematics/college/chhopzlt36x5p3enfbyh66vkslgnjjwhm9.png)
![=\frac{\text{ 210 - 109 }}{12}](https://img.qammunity.org/2023/formulas/mathematics/college/vsslqljgqt56mgnlsj1hurl9ml00m11s5d.png)
![\text{ = }(101)/(12)](https://img.qammunity.org/2023/formulas/mathematics/college/x8a2xb2mtr602tpva7zrbkkpsyzal48r8i.png)
![\text{ = 8 }\frac{\text{ 5}}{12}](https://img.qammunity.org/2023/formulas/mathematics/college/8u44uq56xa93kyekzs9vy1pa0s3xeyztf6.png)
Therefore, the difference in their age is 8 5/12 years.