Question

Which of the following is equal to (2x/3 - 7) + 7?. A. (2x - 7) + 21. B. 2x - 21/3. C. 3x/2. D. 2x/3.

Answer 1

For this case we have the following expression:

$(\frac{2x}{3} - 7) + 7$

What we must do in this case is to use one of the properties of the sum.

In this case, we must use the associative property.

The associative property states:

$(a + b) + c = a + (b + c)$

We have then:

$(\frac{2x}{3} - 7) + 7 = \frac{2x}{3} + (- 7 + 7)$

Simplifying we have:

$(\frac{2x}{3} - 7) + 7 = \frac{2x}{3} + (0)$

$(\frac{2x}{3} - 7) + 7 = \frac{2x}{3}$

Answer:

the following is equal to (2x / 3 - 7) + 7

D. 2x / 3.

Answer 2

(2x/3 - 7) + 7

Remember the order of mathematical operation, PEMDAS.

first, solve the operation inside the parenthesis.
2x/3 - 7 = 2x/3 - 7 * 3/3 = 2x/3 - 21/3 = (2x - 21)/3

In adding or subtracting fractions, make sure that each term have the same denominator.

Then the operation outside the parenthesis,

(2x - 21)/3 + 7 = (2x-21)/3 + 7 * 3/3 = (2x - 21)/3 + 21/3 = 

(2x - 21 + 21) / 3 = 2x/3

The final answer is D. 2x/3