Evaluate the numerical expression.

1 over 2 − (−3 over 4)

To evaluate the numerical expression 1 over 2 − (−3 over 4), we need to simplify and compute the values.

First, let's convert the fractions into a common denominator:
1 over 2 − (−3 over 4) = 4 over 8 − (−6 over 8)

Next, perform the subtraction:
= 4 over 8 + 6 over 8
= (4 + 6) over 8
= 10 over 8

Finally, simplify the fraction:
= (10 ÷ 2) over (8 ÷ 2)
= 5 over 4

Therefore, the numerical expression 1 over 2 − (−3 over 4) evaluates to 5 over 4.

Simplify.

7.829 − 3.21

To simplify the expression 7.829 − 3.21, you subtract the two numbers.

7.829 − 3.21 = 4.619

Therefore, the simplified expression is 4.619.

32 + (−72.1)

To simplify the expression 32 + (−72.1), you add the two numbers.

32 + (−72.1) = -40.1

Therefore, the simplified expression is -40.1.

42.86 − 23.42

To simplify the expression 42.86 − 23.42, you subtract the two numbers.

42.86 − 23.42 = 19.44

Therefore, the simplified expression is 19.44.

Consider this expression:

1 over 4 − 0.5 + 1 over 2 − 0.25 + 3 over 5 + 0.4

You are asked to find the sum by using fractions. Which expression could you use?

To find the sum by using fractions, we can rewrite each decimal as a fraction and simplify the expression:

1 over 4 − 0.5 + 1 over 2 − 0.25 + 3 over 5 + 0.4

Converting the decimals to fractions:

1 over 4 − 1 over 2 + 1 over 2 − 1 over 4 + 3 over 5 + 2 over 5

Combining like terms:

(1 over 4 − 1 over 4) + (1 over 2 − 1 over 2) + (3 over 5 + 2 over 5)

Simplifying each set of fractions:

0 + 0 + 5 over 5

Finally, combining the fractions:

5 over 5

Therefore, the sum of the expression 1 over 4 − 0.5 + 1 over 2 − 0.25 + 3 over 5 + 0.4, using fractions, is 5 over 5.

To evaluate the numerical expression 1/2 - (-3/4), follow these steps:

Step 1: Simplify the subtraction of two fractions.
To subtract fractions, you need to have a common denominator. The common denominator is the smallest multiple of the denominators (2 and 4), which is 4.

- Rewrite 1/2 to have a denominator of 4: (1/2) x (2/2) = 2/4
- Rewrite -3/4 as it is.

Step 2: Perform the subtraction.
Now that both fractions have the same denominator, you can simply subtract the numerators.

2/4 - (-3/4) = 2/4 + 3/4 = (2 + 3)/4 = 5/4

Step 3: Simplify the fraction (if possible).
The fraction 5/4 cannot be further simplified because 5 is a prime number and 4 is not a factor of 5.

Therefore, the value of the numerical expression 1/2 - (-3/4) is 5/4.