Answer:
Option 'b' i.e. -11/20 is the correct option.
Thus,
![(1)/(5)-(3)/(4)=-(11)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/56k0jcacvbh2pcronjb9elpcdom5qfcrei.png)
Explanation:
Given the expression
![(1)/(5)-(3)/(4)](https://img.qammunity.org/2021/formulas/mathematics/high-school/yiz0aq959a5i9lumu1u8mwfijspq2llmge.png)
Determining the difference of the fractions
![(1)/(5)-(3)/(4)](https://img.qammunity.org/2021/formulas/mathematics/high-school/yiz0aq959a5i9lumu1u8mwfijspq2llmge.png)
The Least Common Multiplier of 5, 4 is 20. Thus, adjust the fractions based on the L.C.M.
![(1)/(5)-(3)/(4)=(4)/(20)-(15)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/qa3osna180p2lqd371tt4dxiv5013vrrnh.png)
Apply the fraction rule:
![(a)/(c)-(b)/(c)=(a-b)/(c)](https://img.qammunity.org/2021/formulas/mathematics/high-school/g6q9sppo1udjjec5kzogqzn3myk6z2zckg.png)
![=(4-15)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/jeh1qzngnbr01nxfzvk0ivkzu9qz82vy94.png)
Add the number: 4-15 = -11
![=(-11)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/7wj0oc6lyz31i5d50buo33pznp8smrxv9x.png)
Apply the fraction rule:
![(-a)/(b)=-(a)/(b)](https://img.qammunity.org/2021/formulas/mathematics/high-school/2r6sa1sns2l4ukebxa0tnr20oukhizom27.png)
![=-(11)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/sfzjvl1tohal4s927dkylbvxb4pk0jjch9.png)
Please check the attached figure, where the pointing-down arrow is representing the correct answer which is -11/20.
Therefore, option 'b' i.e. -11/20 is the correct option.
Thus,
![(1)/(5)-(3)/(4)=-(11)/(20)](https://img.qammunity.org/2021/formulas/mathematics/high-school/56k0jcacvbh2pcronjb9elpcdom5qfcrei.png)