Explore Westonci.ca, the premier Q&A site that helps you find precise answers to your questions, no matter the topic. Join our Q&A platform to connect with experts dedicated to providing precise answers to your questions in different areas. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

How do you know that the sum of [tex]\(-2 \frac{3}{4}\)[/tex] and [tex]\(\frac{5}{9}\)[/tex] is rational?

A. The sum is a terminating and a repeating decimal.
B. The sum is a non-terminating and a non-repeating decimal.
C. The sum is a fraction.
D. The sum is an integer.


Sagot :

To determine the sum of [tex]\(-2 \frac{3}{4}\)[/tex] and [tex]\(\frac{5}{9}\)[/tex], follow these steps:

1. Convert the Mixed Number to an Improper Fraction:
- The mixed number [tex]\(-2 \frac{3}{4}\)[/tex] can be converted to an improper fraction:
[tex]\[ -2 \frac{3}{4} = -2 - \frac{3}{4}. \][/tex]
To do this, write [tex]\(-2\)[/tex] as [tex]\(\frac{-8}{4}\)[/tex]:
[tex]\[ -2 = \frac{-8}{4}. \][/tex]
Now add these two fractions:
[tex]\[ -2 \frac{3}{4} = \frac{-8}{4} + \frac{-3}{4} = \frac{-8 - 3}{4} = \frac{-11}{4}. \][/tex]

2. Add the Two Fractions:
- Now, we need to add [tex]\(\frac{-11}{4}\)[/tex] and [tex]\(\frac{5}{9}\)[/tex]:
[tex]\[ \frac{-11}{4} + \frac{5}{9}. \][/tex]
To add these fractions, find a common denominator. The least common multiple of 4 and 9 is 36.

Convert each fraction to have the common denominator:
[tex]\[ \frac{-11}{4} = \frac{-11 \times 9}{4 \times 9} = \frac{-99}{36}, \][/tex]
[tex]\[ \frac{5}{9} = \frac{5 \times 4}{9 \times 4} = \frac{20}{36}. \][/tex]

Now add them:
[tex]\[ \frac{-99}{36} + \frac{20}{36} = \frac{-99 + 20}{36} = \frac{-79}{36}. \][/tex]

3. Simplify the Result (if necessary):
- The fraction [tex]\(\frac{-79}{36}\)[/tex] is already in its simplest form because 79 and 36 share no common divisors other than 1.

The sum of [tex]\(-2 \frac{3}{4}\)[/tex] and [tex]\(\frac{5}{9}\)[/tex] is [tex]\(\frac{-79}{36}\)[/tex]. This is a fraction, so the correct answer to the question is:

The sum is a fraction.

Additionally, the sum [tex]\(\frac{-79}{36}\)[/tex] when converted to decimal form is approximately [tex]\(-2.1944444444444446\)[/tex], which is a non-terminating, repeating decimal. The decimal form repeating part, however, reassures that [tex]\(\frac{-79}{36}\)[/tex] is a rational number.

The sum is rational.

Thus, the correct answer is also that the sum is a terminating and a repeating decimal.

In summary:
- The sum is a fraction.
- The sum is rational.

However, for the answer format given, selecting "The sum is a fraction" would be the simplest and most directly relevant choice.