Exercise 13 Page 250

Practice makes perfect

When adding or subtracting fractions, they should have the same denominator. In this exercise, we have two fractions with different denominators. 2/3 + 4/5 First, we can list the multiples of 3 and 5. Multiples of $3$:&3, 6, 9, 12, 15, ... Multiples of $5$:&5, 10, 15, 25, 30, ... Since 15 is the least common multiple of our denominators, we can first multiply both the numerator and denominator of 23 by 5 to create a common denominator.

2/3 + 4/5

ExpandFrac

a/b=a * 5/b * 5

2* 5/3* 5 + 4/5

Multiply

10/15 + 4/5

Next, we can multiply both the numerator and denominator of 45 by 3 to create a common denominator.

10/15 + 4/5

ExpandFrac

a/b=a * 3/b * 3

10/15 + 4* 3/5* 3

Multiply

10/15 + 12/15

Now that we have a common denominator, we can proceed to simplifying the expression.

10/15 + 12/15

AddFrac

Add fractions

10+12/15

AddTerms

Add terms

22/15

FracToMixed

Write fraction as a mixed number

1 715

When we multiply fractions, we need to remember that the product of two fractions is equal to the product of the numerators divided by the product of the denominators. Let's find the given product!

(4/5 )(2/3)

MultFrac

Multiply fractions

4* 2/5* 3

Multiply

8/15

When adding or subtracting fractions, they should have the same denominator. In this exercise, we have three fractions with different denominators. 4/5 - (- 2/3) First, we can list the multiples of 5 and 3. Multiples of $5$:&5, 10, 15, 25, 30, ... Multiples of $3$:&3, 6, 9, 12, 15, ... Since 15 is the least common multiple of our denominators, we can first multiply both the numerator and denominator of 45 by 3 to create a common denominator.

4/5 -(- 2/3)

ExpandFrac

a/b=a * 3/b * 3

4* 3/5* 3 -(- 2/3)

Multiply

12/15 -(- 2/3)

Next, we can multiply both the numerator and denominator of 23 by 5 to create a common denominator.

12/15 -(- 2/3)

ExpandFrac

a/b=a * 5/b * 5

12/15 -(- 2* 5/3* 5)

Multiply