• Given the fraction 5 out of 7, you can write it as:
![(5)/(7)](https://img.qammunity.org/2023/formulas/mathematics/high-school/4kq3i9oroaoy4ez6jsc2triag9f3udavvm.png)
Where 5 is the part and 7 is the whole.
Notice that, in order to obtain 15 out of 21, you need to multiply the numerator and the denominator by 3:
![=(5\cdot3)/(7\cdot3)=(15)/(21)](https://img.qammunity.org/2023/formulas/mathematics/high-school/x09y27hremy06x6el3vfnwf6fweb13w63i.png)
• Given the fraction 30 out of 50:
![(30)/(50)](https://img.qammunity.org/2023/formulas/mathematics/high-school/f4phiw5r8rncm080a1is0o8bmd0ojrvskl.png)
You need to divide the numerator and the denominator by the same number, in order to reduce it. If you divided them by 5, you get:
![=(30/5)/(50/5)=(6)/(10)](https://img.qammunity.org/2023/formulas/mathematics/high-school/oxx3gn4i5tpc0ix4v8h2crzu7cq4dukjvl.png)
Hence, the answers are:
• Multiply its part and whole by:
![3](https://img.qammunity.org/2023/formulas/mathematics/college/8chu5ttn7pbn22os4jpmgusjicxxbd8h.png)
• Divide its part and whole by:
![5](https://img.qammunity.org/2023/formulas/mathematics/high-school/q35gspm3osqm4gl92d1u7bydqn7g6fougf.png)