Question

Miguel made a shirt using 1/4 meters of red fabric and 4/5 meters of green fabric. How many more meters of green fabric did Miguel use?Write your answer as a fraction in simplest form

Answer 1

Given data:

1/4 meters of red fabric

4/5 meters of green fabric

To find how many more meters of green fabric he used you subtract:

`(4)/(5)-(1)/(4)`

Follow the next guide for subtraction of fractions with different denominators:

`(a)/(b)-(c)/(d)=(ad-bc)/(bd)`
`(4)/(5)-(1)/(4)=(4\cdot4-5\cdot1)/(5\cdot4)=(16-5)/(20)=(11)/(20)`

Subtraction using LCD:

1. List the multiples of the denominators (first 5 multiples):

`\begin{gathered} 5\colon5,10,15,20,25 \\ 4\colon4,8.12,16,20 \end{gathered}`

2. Identify the LCD: In the given case the LCD is 20

3. Rewrite the fractions using the LCD:

To rewrite the fractions, multiply numerator and denominator by the number that makes the denominator be equal to 20

`\begin{gathered} (4)/(5)\cdot(4)/(4)-(1)/(4)\cdot(5)/(5)=(16)/(20)-(5)/(20) \\ \\ \text{Subtract:} \\ =(16-5)/(20)=(11)/(20) \end{gathered}`

Answer: 11/20 meters